Independent mechanic fixed A/C but said it may happen again. It did and had to bring to dealer. Mechanic drove car, said it worked fine, charged $35. 3 miles down the road, A/C quit blowing cold air again. Went back to dealer next week after independent mechanic showed me computer program he had stating what to do and dealership did that. A/C is still doing the same thing and I can't understand with the computer programs they have why they can't fix the stupid A/C without me having to tell them what to do and if that doesn't fix the problem, what to do next. I called GM Customer Service and received letter from them they couldn't reach me at the phone number provided and will call them back. I don't need a District Specialist, I need someone with the program to tell me what needs to be done next. Also the heater wasn't putting out heat back in March and it's been extremely hot so haven't tried it again, but had a problem in years past with Pontiacs - cable to heater breaking and needed to be replaced.