If you get a good grade of vinyl, not the cheap-o stuff, it will conform to curves and bumps fairly easily. You can use heat to help make it conform to tough areas, but take care not to heat it up too much, as it will start to stretch , and then get distorted.

Are you doing large shelby-style stripes over the top of the car? If so, doing them in sections (i.e. hood, roof, trunk) is the way to go, so you're not having to fight with one long stripe.

I don't remember what kind of car you were going to do the striping on, but you should be able to do it with no problem, just take your time, and get a plan of attack before you go to stickin' it down...take into consideration spoiler, etc...some "bolt on" parts are easier if you take them off, do the main striping, and then go back and stripe the other parts seperate...

Good luck, and ProZ will probably have some other things to add that I forgot...