Aallman,
Monokote Trim is an interesting thought, I use Monokote for my RC planes, just never thought of using it for an actual car. It super thin, and extremely tough stuff. That's not to say that if a rock pings your car, that it may not be torn. Just make sure you really clean the area where it will be applied. Since is soooooo thin, any little bump will show. Get a good wide burnisher, and make sure to start at one end and work evenly toward the other end...do this in the shad not in sunlight. otherwise you'll get bubbles (you can use a pin to pop bubbles if you do get them). Take some pics and let us see your masterpiece.