Pulled the back tire off today on the drivers side to do the brakes.I notice alot of sand and dirt on top of the spring plate so I removed it and sure enough there was corrosion under there.Then I preceded to remove the cover on the filler pipe and there must have been at least a half of a inch of dirt in there.Is there some way to cover these areas to prevent premature rust?What was GM thinking with all these openings.