I purchased a used Cadillac CTS from Bill Jacobs in Joliet, IL (Jefferson St.) I paid for the car with my trade a 07 Hummer H3 in perfect working condition. I was also to receive payment in cash from the dealership for the difference, which to date I have not received. Within 24 hours the car started to vibrate, I contacted the dealer prior to 24 hours being up and notified them that there was something wrong with the car, that had already been certified by the dealership mechanics. I brought the car in for service, and was given a loaner. I explained to several representatives that I was concerned that the car was not reliable and did not have a good feeling about keeping the car due to it being certified by a mechanic and still having mechanical difficulties. The dealer offered to fix the vehicle, I oblidged. The service manager stated that there was an issue with the tires, possibly due to the rims but he needed additional time to determine what the issue was. I spoke with the sales manager and told him that my confidence in his dealership was 0 and that I wanted to just give them the Cadillac back and take my reliable car back. John the manager stated that was not going to happen. I explained to him that the car was sold with a mechanical defect and that I had no confidence that this would be a reliable car. I went into the dealership today (09/11) the third day with no car and explained that I was not comfortable with the dealership or thier ability to provide a reliable car to me in the price range that had been negotiated with the previous deal. They outright refused to give me my trade in back and said it was too late. They were unwilling to sell it back to me at the price of the deal for trade and recommended I pick another car on the lot. As was the issue with my original visit, there was no other car I was interested in. I like the car I bought and would have been a pleased consumer had that car not been a defect. I of course became hysterical because the dealership was unwilling to use the three day rule and would not even listen. I do not trust these people and I am not comfortable buying or keeping any product that they offer, as the sales manager and another manager stated "sometimes one slips through the cracks" or "if it breaks just bring it back we'll keep fixing it" - how many times do I need to do that. I simply don't understand why the dealership will not recognize the breach of contract and reverse the deal. I think this is criminal behavior and poor customer service. I realize they are willing to fix the car, but there is no guarentee that this is a sound or safe vehicle for my family to travel in.