If your looking to do some racing type side stripes on the cheap there is a company called monokote that makes sheet adhesive backed trim product called "Top Flite Trim MonoKote" for model airplanes/cars/boats that is water and fuel (r/c fuel I guess) proof. They also make a remover for the adhesive I believe but most goo-gone type products should work.

It comes in about 30 colors/patterns. I picked up some yesterday at a local R/C shop for $2.89 for a 5" x 36" sheet. The color is called "aluminum" and is a metal flake look that matches the silver trim on the Crossfire pretty close. Its a really thin film so once its on it looks like paint. With it being so thin I don't know how well it will stand up to grit/sand/dirt hitting it at 60 mph but since its so cheap and comes off, it should be good to play with.

You can also purchase it online:
http://www2.towerhobbies.com/cgi-bin...?&I=LXHX83&P=7

Here is a list of colors:
http://www2.towerhobbies.com/cgi-bin...P?&C=QAE&V=TOP

Most hobby shops that carry r/c airplane stuff should carry it. Also the "chrome" and "gold chrome" colors are a mirror type material, not the solid color that is shown in the link.

Enjoy!