I did the Avery brand Clear bra protection on my red Crossfire (3M product is probably exactly the same). Does definitely prevent 99% of stone chips. A big one will still dent the front clip, and a few chips will still inflict damage to the paint right where the clear bra ends...the film gets to the edge of a panel to about 1/8 of an inch, but after enough miles a few stones will find those tiny little areas all across the front. I ended up with around 5 good chips right at the edges after 21k miles of freeway driving in Phoenix.

The film does slightly stain over time from dead bugs (every cleaner I tried made it worse), and the film adds a look of heavy orange peel to the paint (lots of people commented on that). Also, it slightly yellows over time, but probably only apparent on white cars...I didn't notice it on my red after 2 years. Another thing I noticed is that it looks as if it shrinked just a tiny little bit...noticed that all the edges pulled back maybe 1/32 of an inch everywhere, not really a big deal there.

Also, when you wax the car, wax will get into the edge of the bra, which adds up to 25 or 30 feet of perimeter that you will have to detail to get the wax out...or prevent wax from getting into that area when applying in the first place. Some have said that isn't a problem, apparently it depends on your wax brand and/or method of application and detailing. For me, it was a big issue...it was very apparent on the red.

Also, it is relatively expensive. I paid around $400 installed for the full kit, which covered 1/3 of the hood, both headlights, fog lamps, entire front end, and side view mirrors.

Overall, though, a very nice product.