called GMC customer service to complain and to see if there is any recall as i noticed there seem to be a lot of comlaints on the internet, they say unless people complain directly to them they do not recognise there is any problem ie with the roofs on these vehicles .Told me to go to a dealer to have this fixed that means lots of $ i don't think i should have to pay out of my own pocket as this seems to be a common problem with these cars.