Such a simple idea. Now with better materials and a dramatically lower price!

Your doors are held closed by the latch, but they're locked into place with a bracket that slides over a rubber bushing. That makes it easy to align everything, but it means the connection isn't as strong as it could be. In a convertible, the doors provide a surprising amount of structural rigidity if they're properly anchored.

These replace the soft rubber door bushings with a stiff, injection molded, fiberglass-reinforced nylon replacement. The door is solidly locked into place, allowing it to reinforce the chassis. The effect is of a stiffer car with fewer squeaks. We have measured a 3% improvement in torsional rigidity on a 1990.

This is our second generation design, which is now made out of fiberglass-reinforced Zytel nylon resin from DuPont, which makes it even better than the old version. How much better?

3x stronger (tensile stress)
6.5x less stretch (tensile strain)
1.5x more resistant to bending (flexural modulus)
39x better impact resistance (notched Izod impact test)

And just like our previous version, it has good chemical resistance.

In other words, they'll survive for a long time without being treated gently. Like our first generation, the bushing is taller to give 36% more overlap with the door cup. More overlap = less deflection = stiffer car. And on top of all that, they're half the cost of the previous design!

Now available in colors! Choose from standard black, or a bright red. Bear in mind that the color will not be a perfect match for your car - for that reason, we don't recommend (e.g.) red door bushings for a red car. Want a different color? Let us know! We can't do custom colors, but if we hear from enough people we can add more colors.

Fits all Miatas. However, we have had some reports of squeaking from ND3 owners. We are looking into this, as the factory parts are the same as the earlier cars.

Installation is quick and easy - simply remove the two bolts that hold the factory rubber in place and replace with this stiff piece. The door does need to be aligned properly, so if your Miata has an exciting history a bit of tweaking may be required. We've installed them in every car in our fleet.

Sold in pairs, enough for one car.

Black Friday sale - highlights

FM door bushings, second generation