They sell specialty tape for that kind of work in the auto body stores. It is thick as a pinstripe and plastic. This tape gives you a cleaner line when lifting the tape off. You can probably find it cheaper than this if you search.
http://www.autobodysupply.net/3M-06300-1...m06300.htm
http://www.autobodysupply.net/3M-06300-1...m06300.htm

