I did my own last summer. I had roadrash all along the rockers and flares on the Zilla. I've looked at several Bonnevilles over the years, and I think I've determined it'* more likely to be related to the speed you drive than the environment you live in.
Anyway, I rattle-canned mine ON THE CAR using a homemade cardboard mask, then applied a super-hard clear 'chip coat'. You have to be about 6" away from it bent over to even tell I did anything. Came out great, and it'* set to last quite awhile now.