As a current Model car builder as well as a model railroader I use the bare-metal foil on all of the cars I build. You need a new #11 blade in your hobby knife, a staight edge for cutting the stuff, a batch of q-tips, toothpicks and a pair of tweezers. The Tooth picks and the Q-tips are for burnishing the foil on. The surface that you are applying the foil to must be clean and oil-free. Always cut a slightly larger peice of foil than what you need and burnish it down before timming it to size. Be careful because the foil is extremely thin and tear very easily. Try working on a pracice peice for awhile before starting your good work.
Bare metal foil comes in the following colors: Chrome, Ultra bright chrome, Aluminum, Copper, Gold, and Black Chrome.
Other uses for it include using it as a masking medium for painting. Several people that I have talked to tell me that the chance for 'bleed-under' are very slim.
Hope this helps