Brakes Screeeem

When our 2002 Century sets for eight or so hours the rear bakes will screech loud. In very dry weather there not too bad. In damp rainy weather it almost feels like the car shutters. The S/Manager says it is common on the Century and I will have to live with it. I talked to the factry rep Ron Priere and he says there isnt much that can be done. He told me the brake shoes are not covered under warranty and that I would have to pay for new rear brake shoes. He did tell the S/M to remove the drums and take pictures of the brake dust and check everything. He even told him to rotate the tires because they were due.
When I went to check on the car two hours later they were all done. The S/M claims they checked everything and nothing wrong. I asked if he took pictures he said no, his boss had the camera wasn't there at the time. I asked about the brake dust, he said there wasn't any. What??? after 26000 miles? I asked why he didn't rotate the tires. He said he forgot. He claims they checked the runout on drums and front rotors and everything was in spec. This is why I have no cofidence in any GM dealers shops. We have some fine independent shops around here who I have do my out of warranty work. They also claim there there are ceramic shoes that will help my problem. Has anyone had this problem and if so what did you do about it? Thanks for any helpful comments.

I have not heard of this being common. Certainly not on any late model car and not on my Century-a 98 but the rear brakes are the same. I would try new shoes, they are cheap and easy. If you are getting a harmonic tone the you may want to replace the drums as well.