I keep a pair of sunglasses in the car (http://www.solarshield.com/) but the temples usually snap in half after a while.
So I finally got around to 3D printing a replacement.
I also used HIPS to support an ABS print on my dual extruders.
The supports need work. They more or less failed when I tried to print. But well enough to get one good temple to keep me going.
Improve supports (stabilize, maybe with some rocket like fins)
Shorten slightly (the one I printed doesn't quite close cleanly)
cut out between top peg and bottom as that would be where the other temple's other end would rest. So two of these won't quite fold properly.