Two things to check before buying it. First check the codes in the car. Turn the key on. To the right if the steering wheel, hold down the info^ button, and the on/off button for several seconds. The dash will light up then go black. It will then say codes?. Press the on/off button. It will then say all codes?. Again press the on/off button. It will display any codes that are currently in the system. History codes aren't too important, but current codes might be trouble. To exit diagnostics just turn the key off. Second, many Devilles form '00 thru '05 have a 60 to 75 mph shimmy/vibration. During the test drive, get the car between this speed range to check for it. If it exists, sometimes a Hunter Road Force balance will cure it, and sometimes it won't. Definitely not a deal breaker, but can be quite annoying.
Don
