get a 2nd job if ya take to a GMC dealership....
the rear pasenger corner panal has hole, is starting to go on my 2003 silvarado, 160,000 miles....I agree about bondo....make sure you check heater control switch mine goes from 1-5, #4 was only working finally chit the bed also, replaced motor resistor surprised truck did not catch fire...there was a partial recall on the heater units check with the dealership the owner may have got a letter for replacement.... like someone said youtube for do it your self...