I own a 2003 chev Duramax, have replaced injectors (warranty), power window motors both doors, 3 front wheel hub assemblies, brakes, pitman and the black box? On the side of the tranny!
The worst thing about my truck is what they call 'frame beaming' between 60-80kph it bounces like your driving on washboard! GM swears its normal...they will never sell me another truck. When I bought it new it rode like a caddy at all speeds about a year in it started bouncing....if the one you looking at has any wobble don't assume it's a tire out of balance!!