I got rear ended on my bike about a month ago. No severe damage and I wasn't hurt at all. If we'd been in cars we'd have just had scratched bumpers. The collision tore off my rear fender and broke the rear cowl. It's made of ABS and can be bought new and painted for $170... then the stickers are $25 each (x3) so it would have been ~250 to get it back like it was.

I used permatex ABS plastic "weld" epoxy to mend the broken parts and cracks. It's sandable and paintable so it worked as a filler as well. Sanded it smooth and sprayed it with 2 coats of Bulldog Adhesion promoter, then 3 coats of base from Colorite.com ($45 shipped for aerosol) to get the right shade. Colorite says no clear required. I have about $55 and 2 hours in it.

Fortunately it's a matte finish so it was pretty easy to get right. Anyway, here are the pics. I'm very pleased with the results.

http://www.flickr.com/photos/12597488@N06/sets/72157602044807899/