Replacing My Miata’s Broken Plastic Rear Window


I recently (10-1-98) bought a 1991 Red Miata (30,000 miles, not a single door ding or scratch, $7835) and it had a torn and discolored rear plastic window. I looked on the Internet for help and found many articles on replacing the entire convertible top but nothing about quickly and cheaply fixing just the back window.

The back panel of the Miata’s top is designed to be replaced WITHOUT removing the entire top!!! The back panel is the part that unzips and that has the original plastic window inset in the middle. I had to fix mine and I wanted to do it correctly and cheaply.

Mazda sells a replacement back window for $370 and that is just for the clear plastic part, you then need to take it to a shop to have it installed. I did find ads for replacement back panels with a new plastic or glass window but those were also relatively expensive. A catalog sells replacement plastic back panels for $170 and glass back panels for $375. Again you need to have it installed. I see in ads that the zipper half that is on the replacement panel is usually not compatible with the zipper half in the original top, or the zipper comes not sewn on. It is usually required that you remove the zipper from the original back panel and sew it onto the new back panel. What a pain!

I also talked to the local Miata club and they suggested dropping the car off at a specialty/upholstery shop for a rear window transplant. I talked to a few and the prices ranged from $200 to $300. They would remove the top, cut out the window, sew in a new window, and reinstall the top. No one mentioned removing just the back panel but perhaps they all knew how to do it. (I seriously doubt it!!!)

I decided to buy the Miata Enthusiast’s Shop Manual and study it. It includes instructions for removing just the back panel so that the window can be replaced. The advantages are a perfect fit, it’s cheap, the car is not damaged, and it looks as good as possible. If the top is in otherwise good order, this is a great way to fix that broken or brown window.

Please refer to the Enthusiasts Manual for explicit details but I will give you an overview of what to expect if you decide to do as I did. Some steps must be done in a certain order and others can be moved around either a lot or a little. I found the removal took 1.5 hours and the installation took about 1 hour. It was a lot easier than I imagined while reading the manual.

Before I list the steps to complete the repair, I think it would be helpful to give an overview of the convertible top design (this was missing from the manual). The top consists of two pieces; the top and the back panel. Where the top disappears into the body at the back it is attached to a gutter (rain rail) that is used to drain water from the top into drain holes that are in the back corners behind the driver’s and passenger’s heads. This rain rail is a U-shaped piece of plastic and rubber with the rounded part hanging down to channel the rain. Just in front of the trunk is a molding that goes around the where the top is attached. This molding has a rubber flap that hangs down inside the gutter. The back edge of the U-shaped gutter is inserted under this rubber flap so water will drain into the gutter. The top also is inserted into the gutter. All of these pieces rest on and are attached to studs which make disassembly and assembly very easy and straight-forward. Inside the top are three pieces of metal that also push onto the studs, and nuts are screwed on to hold everything in place.

Take the back panel to a shop that will cut out the old window, usually leaving the thermally-glued window edge, and sew in a new window piece (usually to the inside). Have them sew on the Velcro, while they can do it so easily, since it usually comes unglued. The shop I went to did just an OK job. It could have been done better. But I’m the only one who would probably notice.

To reinstall it, do the following:

I hope this helps. I hope I remembered everything. Make sure you get an Enthusiast’s Manual to help you.

Also worth mentioning is the fact that the next time you want to remove the window and replace it, you will be able to do it much faster. Removal in 30 minutes and reinstallation in 30 minutes.

Happy motoring,


Back to the Garage

21 October, 1998