I have a GMC Envoy and I bought an extended warranty. Well, the heater does not work like its supposed to and my rear defrosters are not working properly either Just the top three grids. So I take it to the dealership and guess what? The extended warranty doesnt cover the repairs! The heater needs an actuator that costs $70 which is no problem, but the labor is $600!!! The service manager buys a kit to fix the rear defrosters, but he calls me and says it wont work because there is a bad connection somewhere and the whole back glass would have to be replaced I didnt even ask him how much that would cost!!! Winter is coming (not that we really have much of one, but I do get cold!) so I have a heater that doesnt work that great and no rear defrosters!!! UGH!