Here's my latest project. I'm a bit tall for a Miata, so I removed the visors the first day I had it. This leaves a few holes in the place the visor used to mount. My university happened to have a grant so that students could learn about 3D printing, and I thought, "What is more academic than printing parts for my car?" A 3D printer is basically an inkjet printer that extrudes molten plastic from a roll that looks like weedeater line. It lays down tons of little lines until an object is built like this:
Then you just carve the printing off its base:
They could benefit from a little sanding to make them look a little nicer, but it sure beats random holes in the interior.
Here's a link to the project if anyone happens to see this and has access to a printer to make their own: