I think they go way overboard on the trucks, for me I would rather have my truck overhauled than have 20k worth of stereo and video equipment installed. OH the truck and build a WS, fridge stall and closet into the truck than have all that other jazz.
My wife told me she saw them rebuild (or put in a new) engine in one episode. Youd think theyd do something like that on the older trucks. Take care of some of the breakdown stuff. I remember one thing where the truck was always int he shop...I don't think they ever addressed those issues.