I'll be using 3M Paint Defender on my hood this year:
3M Auto: Products for People Who Love Cars
$24/can, spray on, peel off.
I tested it out an a couple of items and it sprayed well, looked almost optically clear, and peeled off as advertised. I've coated my hood already and it looks pretty good, except for the mosquito that landed in it. I'll write more later as I find out how well it holds up.