OP is there another site at this campground that you could move to? One that's far away from this neighbor?
If not either earplugs or rolling on down the highway are about your only options.
For those suggesting the OP pay for the neighbor's truck to be repaired, keep in mind the neighbor is so inconsiderate they won't even park away from the OP's bedroom window. If I knew my very loud vehicle was waking my neighbors I would be embarrassed and happy to park as far away as possible. This neighbor doesn't even care!
