In a convertible, the door can become a crucial part of the chassis' structural integrity. Your doors are held closed by the latch, but they brace the chassis with a bracket on the door that grabs a soft rubber bushing on the body. This connection makes it easy to align during mass production, but it’s not nearly as secure as it could or should be.
These Miata door bushings will lock the door solidly into place by replacing the soft rubber bushing with a solid Polyurethane version. Not only does a solid bushing stiffen the car for performance benefits, but the stiffer chassis will also reduce squeaks, rattles, and shake/shudder.
Why choose Spiked Performance door bushings over the other 42,069 options on the market? I mean, look at them!
Installation instructions here!