It wouldn't be to hard to do the vinyl work yourself but here is what I'd be worried about. My dad used to run a sign shop when I was a kid and we would do lettering for most hotels limos and what not in Vegas. Anyways, wear and tear up on the windows was bad enough that we replaced vinyl every five years. I can't imagine the peel you'd get from riding the streets. Might want to do some sort of vinyl plus a clear coat over the top if that is possible or even a stencil then clear coat. Anyways, good luck. Cheers.