My current client invented radar and I was BSing with one of the engineers there (trying to get a few cans of the F-117 stealth paint, fat chance!) when he mentioned that one of the prior generation corvettes had a really, really small radar profile. Said that part of it was due to the fiberglass composite exterior which the radar just goes right through and part of it was due to the radiator being tilted back a few degrees. The reason the radiator was tilted was that it allowed for more surface area, but it had the side-effect of angling any radar reflections up into the sky instead of back at the radar gun.

So, I'm thinking that the cladding is probably just as invisible to radar as fibreglass so got that covered better than most cars. But how hard would it be to tilt our radiator or replace it with a larger tilted one? Any comments on the feasability?