CarbonMiata Vent Window Install/Review

(Update: 2/21/2023 and 10/1/23)
This product looked good at first but performs horribly. The short of it: it does not seal against water no matter what you do. The included seals are trash and the engineering has it draining on the INSIDE of the window. Do not waste your money on this!!!

Firstly – hey. Been a while since I had something to blog about. Sorry about the year-plus lapse in posting.

Vent Windows and trim

Working vent windows?!?

THIS is something I’ve wanted for 23ish years of driving a Miata. You’ve wanted it about that long too, though you may not know it. Just trust me. You’ve been waiting forever for this part.

It’s a functional vent window!! It opens the right way, is made of glass, and looks pretty good. Those have been my criteria. See, years ago we got a polycarbonate vent window with the little Cessna pop-out scoop. Then we got another poly one (from Carbonmiata) that opened the wrong way. None have looked very good.

Years and years ago, KG Works started development on a gorgeous, working, glass, correct-direction vent window that never came to light. A few pre-production units were made but nothing made it to the world. I would have paid almost any price for a set…

And then Carbon Miata came out with the above window. After 23 years it was finally time.

Side note – the windows do NOT come with the rubber trim. The OEM part number is NA01-59-651B. That seems to be the number for the set? However, the rubber is different from one side to the other. You need a full set, not just two of the same rubber.

OEM wing windows

Sharka’s stock windows

Over the years, I’ve added a few stickers to Sharka’s wing windows. Stickers that meant something to me or stickers given by friends. Swapping them out is kinda huge for me because they really make me smile. Like… even the next day while writing this, not having these on Sharka makes me a little sad.

But it’s worth it for the possibility of good vent windows.

Anyways, what I’m gonna do with this blog post is a combo install/review for the wing vents. There’s a LOT of NA/NB vent window installs out there, so this is nothing new. But maybe it’ll help a few out.

Vent Window Removal

Remove the window stoppers.

Another view of the stoppers.

You absolutely MUST remove your side windows to do this install. There’s no way to wiggle things into place with this glass vent window like is sometimes possible with a plastic one.

Step 0: Remove the door cards. I didn’t take a pic of that…

Step 1: Remove the window stoppers. Note that the rubber side points down. Also note the position of these stoppers. They can slide up and down to give your window a bit of adjustment in closing. You likely want them in the same spot they’re in before this install.

It is easiest to do this with the window all the way down.

Unscrew the window.

Step 2: Unscrew the window. Each window is held onto the motor/crank with three screws. Unscrew them. This is easiest to do with the window about halfway up. And prepare to argue with that plastic piece covering the door guts.

Lift the window out of the door and carefully set it aside. If you want to install some Delrin window bushings, now is a great time.

Window trim screw.

Remove the window trim.

Step 3: Remove the outer window trim. A hidden screw at the top keeps it in place. Once unscrewed, you can reach your arm down into the door and free the trim from the rail. It goes all the way down into the door. It can dangle at the front of the door over the windshield when freed.

I’ve read this removal as being optional. Trust me, life is easiest when you remove this. You don’t want this in the way while you’re trying to force the new window into place.

The metal trim screw.

Step 5: Remove the metal support screw. Yeah, this gets its own step. These things can get rusty and be a huge pain to remove and install. You’ve been warned.

Metal support bolts.

Remove the support.

Step 6: Remove the metal support. On NBs, this rod has three bolts holding it in place – one is in the middle. NAs just have two bolts – one on each end. Remove them and then you can lift the support out of the door.

Set it somewhere safe. It’s delicate and can’t take being stepped on.

Remove the speaker.

Step 7: Remove the speaker. This is somewhat optional but makes re-install of that metal support rod so much easier. You need to be able to get your whole arm in there to shove the support rod around. Having the speaker hole open makes life better.

Yeah, they’re 25 year old MB Quart speakers. They still sound great and aren’t blown. No judging, k?

Remove the wing window.

Step 8: Remove the vent window! Last step!!! It’s a big deal.

You want to move the window straight backwards along the trim (note the yellow arrow). Don’t yank it upward. Once it slides back a few inches, you’ll feel the gasket release and you can lift it out.

Window Prep

Install the gasket.

If your gasket is still good, you can reuse it on your new wing windows. However, mine are/were original to the car. I didn’t want to reuse rubber from August 94, so I spent the $65 for a new set from Japan.

The gaskets are directional. There’s a beefy segment of rubber that goes on the inside nose of each window.

Note the Carbon Miata branding at the bottom of the window. This was a concern to me as I didn’t wanna see that all the time while driving. I’m happy to report that it is indeed hidden. The door cards touch the bottoms of those screws.

Grease it up.

You MUST use some kind of lubrication when installing these windows, especially if you go for new gaskets like I did. They are gonna be rather large objects resisting insertion into rather small channels. Lube is very much required.

I’m trying to not make a joke. Seriously, they can’t go in dry. They’ll break first.

I used Shin-Etsu grease on mine. It’s sometimes known as Honda grease. They suggest it for all door gaskets, hardtop gaskets, trunk gaskets… any sort of opening. And it’s brilliant. I’ve had this tube for years. It may be a lifetime supply.

Spray silicone works well too, but an actual grease will stay on the gasket longer and make installing that much easier.

Window Install

Greased up.

Step 0: GREASE UP. Did you skip the above prep?

The real trick to this install involves those two rectangular raised areas. They need to get underneath the door metal first.

Gasket under the door.

Step 1: Get the gasket under the door top edge. See how the rectangular bits are now hidden under the door metal? That’s the whole trick to this install. If you try to get the top edge in first, the window will fight you the whole way. If you get the bottom edge in first, it’s cake to install.


Slide the window forward.

Step 2: Slide the window forward. The window needs to move forward until the edge is even with the top edge of the metal frame.

Step 3: Put everything back. Not photographed.


And now it’s done!!! Looks really nice doesn’t it? Just one thing left to do.

Vent Window Review

Working vent windows.

I’ve waited so long.

They work. Air swirls around the cabin in a pleasant manner with both open. Crack a window and a lot more air flows through.

Carbonmiata says they open about 50 degrees. That seems about right. They don’t spin all the way around.

And yes, this IS the correct way for a vent window to open. Opening the other way results in a ton of air spraying you straight in the face and/or a window smashing itself against the mirror. They’re meant to be vents.

10/1/2023 update – They do NOT stay open in warm weather. They rather quickly shut themselves back down. You can prop them open with the little handle, but you don’t get much of an opening that way nor much airflow. They stay open in cold winter weather, but nothing else… pretty horrible.

Mirror clearance.

Mirror clearance.

This was the $499 question basically – would they even work on Sharka with his Runabout M2 mirrors. Happily, the answer was yes, they do fit. The windows couldn’t be much larger and work though. It’s a really tight fit.

Interior view.

Interior view.

For me, this was also a make-or-break question – is that horrible logo at the bottom visible? Nothing against CM or their logo. I don’t want MY OWN logo at the bottom of the window either. I just want it to look OEM. Or OEM+ as it were.

I’m very happy to show these photos off – the first I’ve seen of these vent windows from the interior. They look really great from the driver’s seat honestly. REALLY great.

Vents. Ahh.

Is there a down side? Yeah. It’s noise.

These add a fair bit of wind noise to the car above 60 MPH. Air whistles past the very-not aerodynamic square profile gasket and bare edge glass. And this is with the windows closed – let me make that clear.

They make noise when closed.

I wouldn’t be so picky to complain about wind noise when open. And there is some, but it’s similar to having windows down. Above 85 they scream when open, but so does the window itself. That’s totally fine.

With a crosswind, you can hear the closed vent windows above 40 MPH. On a calm day, it takes till freeway speeds to hear the increased wind noise. It’s not terrible, but it is surprising. I needed to mention it in this review.

The Scorecard

Build Quality: Good. The gasket is rubber, the glass is real, the frame is plastic, and they’re the right shape. The glass is supported by a metal frame and the hinge is smooth. They close very tightly. But the outer edge is not aerodynamic. There’s a ton of right angles and small channels that wind loves to whistle through. B-

2/21/2023 Update: These windows leak like crazy when any water at all gets on the glass. They drain inside the interior right over the door card. Engineering was apparently limited to making them open and close and water tightness was forgotten. The build quality score drops to an F.

Installation: Not difficult and nothing special about it. They install like any other vent window and aren’t delicate. You’re not worried about breaking them at any time during an install. No issues at all. A+

Usability: They work… sorta. When fully open they let in a nice amount of air. However, they cannot stay fully open on their own in weather above 50*F. They shut by themselves at speed. C-

2/21/2023 Update: As mentioned above, these things leak like a screen door. I’ll be trying to fix them in another post, but… for right now the Usability score drops to an F.

Style: Not as beautiful as the fabled KGW vent windows, but pretty damn good. Good enough for me to spend $499 on them. I love the look and think an A is the lowest possible score I could give for the style.

Overall: These things look okay but that’s their only benefit. They are poorly engineered, leak, and do not stay open. Do not waste your money. They get an F. Sorry.

Sharka missed his blog.

The subject of this photo is that vent window. Really.

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  • Erick Arauz says:

    Would be sweet to get some in cabin videos to hear that wind noise. Excellent review!

  • ManiacLachy says:

    Thanks for the install/review, and for a blog update! We all missed Sharka.

    They look a lot cleaner than I thought they would, when you see the whole frame uninstalled they look ungainly, but once installed they look great. Shame about the wind noise though.

    I imagine when combined with the Bikini Top in summer you’d get a great flow of air to keep you cool. I hope you can do a follow up in July to let us know how that goes – can it beat the summer heat without AC?

    • revlimiter says:

      I’ll try to update! I’m also curious about summer / bikini functionality. Or at least water tightness when getting washed…

      • revlimiter says:

        sadlol. water tightness…. If only I’d known…

        • ManiacLachy says:

          Yep, such a shame about the water-tightness! I saw your Instagram post and the amount of water flowing in was shocking. So much water you’d think it was a design feature to bring water in on purpose.

          Good luck with the fix, keep us posted.

  • Eric Hedberg says:

    Been teetering on the edge about these having missed having vent windows for a few decades on any car. This might just tip me over.

    Thanks for the always excellent review and installation details.

  • Daniel says:

    Thanks for the update,i really enjoy seeing Sharka´s progression and you are a big source of inspiration for Alfred, my na8c 🙂

  • Elwin says:

    I’ve been considering these for a while, they look great! My main concern with it was the water tightness and visibility out of the window, really too bad to hear they don’t seal well… Especially considering the price. Do you think it is a manufacturing defect? Or just a lack of testing/design? It could have been a great product from CM! Thank you for always trying things out and writing so detailed about them. Guess I’ll stick to the OEM windows for now 😛

    • Graham says:

      Unfortunately, I have seen from a few other individuals that their CM vent windows leak just as bad, and regret paying $500. Hope this helps!

  • Guy says:

    Hi Adam, great review on the opening quarterlight kit.
    Very sad to see that they’re not watertight, an absolute must here in the UK.
    I thought they looked superb and have been following their development. I was close to buying a set so thank you for taking the pain on our behalf.
    Do you know if there are any plans to re-design the seals after your feedback?

  • Oskar says:

    Shame the build quality turned out to be bad, I had been waiting for these as they would’ve fit my build. Maybe someday we’ll get better vent windows available.

  • dani says:

    That sucks, I got their Sequential LED Tail Lights V2 in RGB and they are horrible, the key fob doesn’t work at all and the app wont control them half the time. I tried to contact them and they basically said too bad. They worked for about a week then just started acting strangely. Bummer because the products listed seem awesome but doesn’t seem like they have great customer service.

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