We took our Grand Prix in for some warranty work. Later that day, one of the service guys called to try to convince us that we needed to give them $200 for a much needed thermostat replacement job. He went on for a long time about why it was so necessary and important. (I have changed MANY thermostats in the past and have rebuilt entire engines, cars, and trucks myself so I have a thorough knowledge of their necessity.) He also wanted to charge us $40 for changing the cabin air filter. The T-stat cost me $6.99 and the Cabin air filter cost me... read full review »