I have a 2003 Silverado with rust bubbles under the paint around the cab's rear brake light. I took my truck in today to the dealer where I purchased the truck and was told this would normally be covered (my corrosion warranty expires June 2009), but because I am a coastal resident, the warranty would not be honored. I have had neighbors who have had rust repairs in the same location from the same dealer. Does the Service Manager have enough power to pick and choose who is covered and who is not ? I called GM Customer Service and said they could only go by what the local manager recommends. Also, when I purchased the truck, I was told the corrosion warranty would be honored no matter where I lived. Any suggestions on what to do next ?