I'm a skeptic, I can't see any spray on product protecting against the damaging UV rays of the sun. Best bet is to try and park in the shade whenever possible.
I've tried the various waxes I've had on hand, including 845 and GG 3-in-1, and none of them provide more than a temporary fix.
Have just been too lazy go out and source a can of clear coat for a more durable solution.