I plasti-dipped the hood on my Dodge Challenger and it has lasted three years with no problems. I even used pressure washer on it. But, you do have to be careful. If you get a small piece peeling and hit it with the high pressure, it will peel right off.
My son plasti-dipped the front and rear bumpers on his Subaru, and the wheels and they lasted for two years before he sold it.
Plasti-dip does hold up well. Having said that, I never drove the Challenger through trees so can't tell you if it will hold up to being scraped by branches.
One other thing. If you spray it on, make sure you are in the shade. I sprayed my hood in the direct sun, and it had a rough finish. At first I didn't like it... called the company and they told me it dried too fast. But, more I looked at it, it was kinda cool and different, so I left it.
Mike