I used plastic razor blades and 3m adhesive remover followed by OCP/white pad on a friend's camaro I did, it came out perfect. The plastic razor blades are espicially helpful in the wheel wells.
Not that I should encourage such behavior
, but they make a product called burnout guard, you spray it on and after you light 'em up to your heart's content, all you've gotta do is spray the quarterpanels down with water and the rubber will come right off.