I plasti-dipped over the chrome fuel filler cover on my jeep . . it looked really good . . . until I filled up with fuel and some dripped on it The petrol just dissolved and ate it away . . I will be re-doing with Truck Bed Liner
So be warned, Plastidip + anything other than water = ball ache. Petrol is prob the worst, but what about a small oil spill, or over spray from window cleaner.
I would get a small sheet of metal and spray it your self, then test different liquids etc that your car could come in to contact with.
Also . . if lets say there was a small rip or tear . . all those people who pick scabs would not be able to resist picking another bit off, before you know it you come out of tesco's to find most of your bonnet has been "peeled"