blue painters tape.
make sure it's LOW adhesive. It should have the marking on the wrapping if it's the 3M stuff.
I use it everytime I go to the track, leaves my front end, my skirts in mint shape everytime after. 2 rolls last me 3 track days, and it's only 10 bucks a roll up here. Beats getting a stone chip, that's for sure.
blue tape trees haven't filed a protest on me abusing it yet