US / cars 20 Worst Used Cars Compiled by Consumer Reports By Dustin Lushing, Newser Staff Posted Mar 24, 2012 1:30 PM CDT Copied A 2008 Cadillac STS. (AP Photo/Cadillac) The only thing worse than buying a lemon is buying a used lemon. Here's a list of 2012's worst used cars compiled by Consumer Reports and courtesy of ABC News. Audi Q5 (V6): Reported problems in 2002-2011 included engine cooling, body integrity, and especially the audio system. BMW 535i: The 2008-2011 models showed technical difficulties in the fuel system and the electrical system. Cadillac STS: "A total nightmare," says Consumer Reports. Production was halted after the 2011 model. Dodge Grand Caravan: Once top of the line in its category, the old Grand Caravans are riddled with problems in their brakes, climate system, and body integrity. Ford Thunderbird: The faux sports car was taken out of production in 2005 after troubles with the engine, electric system, and transmission. Check out the whole list here. (More cars stories.) Report an error