I had the 3M film on my Acura, and took several rocks that went right through it. I finally gave up and removed it. I'll probably have to get the front end repainted in a couple of years, but that's life in a shipping port that's in the midst of a construction boom (Charleston, SC).
I don't have a Cobra, but I do have a Porsche Speedster replica, and I had a custom bra made by Wardlow Custom Masks (
www.wardlowbras.net). I was the first normal body Speedster they'd done, so it took a couple of tries to get it right, but it really fits tightly and covers the front 1 1/2 - 2 feet of the car. The service from these folks is wonderful. Ask for Kristina.
As for the tales of paint damage, they're true IF the bra fits loosely and/or you leave it on all the time. You should
never put one on a dirty car, nor should you leave it on for an extended period if it's wet, as the trapped water can cloud the paint. I plan to drive from Charleston, SC to Carlisle, PA next week with it for it's first extended test, but so far I've seen no flapping whatsoever.
When I get home tonight I'll post a couple of pictures, if anyone's interested.