Rayne

I was wondering what you guys would recommend to do to the front of the car before applying the clear bra. Should I wax it? I'm guessing not, as it would prevent the bra from sticking. Should I go over the paint with swirl-x or something else, and buff it really well?
P.S. The car has 38K miles on it, and have a few scratches and chips. But it's not too bad yet. Aside from the bumper, mirrors, and hood - should I do a few inches of the roof above the windshield?
TIA