dealership i used to work at used to have cars done all the time and lend cars out to the company that did them for demos. they would wrap and un-wrap the whole car several times a day during the demos. it goes on pretty easy if you take your time if you mess up just pull it back off and try again.
ive seen it left on a car for over a year and came right off and left nothing but a clean paint job underneath. only thing you wanna make sure you do if your gonna leave it on for a while is to cover all paint on the body so it doesnt fade uneven.