Put the key in the ignition, heard a very cranking/banging noise, then the air conditioner did not work. Hot air coming out of the vents instead of cold air. Had the car 2 weeks, bought it used at Carmax under "certified vehicle" warranty. Can't believe the air conditioner stopped working at 24,260 miles! Hopefully, Carmax will stand behind their sale and fix it RIGHT; and hopefully this 2008 Buick Lucerne is not a lemon! Had two lemon cars bought brand new before, did not need another lemon one! The engine was very quiet at start-up, so I am very concerned that there is more to it than the air conditioner alone giving out... The noise it made when I started the car was definitively loud...