What material to construct armrest out of?

On 3rd gen RX-7s, there is a map pocket with a lid in the driver's side door panel. The lid always breaks. It also happens to be just where one might rest their arm. I was thinking the hole left behind with the lid removed would be perfect to receive a padded armrest. I'd like to make such an armrest. Was thinking of ways to do it, but not sure what would be the best.

• Line spare door panel hole with plastic wrap and fill with great stuff. When hardened, remove and use as a base to fiberglass up a "plug" for the hole. Cut and glue foam and wrap in faux leather.

• Create mold from block of foam, do a similar thing with fiberglass.

• Use modelling clay to make a more accurate mold of all the niches and crevasses in the door pocket.

Here's what the hole left behind with the pocket door off looks like. It has some features for the hinges etc that may need to be accounted for. Ideally I'd fill in all the space to be flush with the rest of the door panel.

Any ideas? Is fiberglass the right way to go or...? Thanks!

Personally, I would get some scrap MDF and cut it until it fits well, then vinyl stretch over it and call it a day. Fasten it with epoxy or something. Put a time capsule in it so when someone eventually breaks it they have something cool to find.

I'm not sure I'd use foam as it may not be quite dense enough. I would be more inclined to either take Taiden's advice or come up with a sort of "hybrid" of your original idea and Taiden's.

Most armrests I've ever found in cars were too soft and as a result were useless.

I would not use furniture foam.. but maybe something like this rubber padding. It is closed foam and much stronger, thicker, and more resistant than chair padding

Rubber Pilates Pads

Any ideas? Is fiberglass the right way to go or...? Thanks!

Use this:

I doubt you could remove that thumb from Chuck Norris to use it... but it would make your car invincible

his finger nail clippings would be sufficient

I made one out of Zebra Wood; dense as metal, cover it with Poly.