If you know your dealer is **** hot at diagnosing electrical problems and 110% honest, that will work. Otherwise, you might wind up paying parts & labour for the 17 year old shop apprentice to gain "experience" replacing every electrical part (and the bits he breaks along the way) in a hit-or-miss attempt to fix a problem that no one else in the garage will touch because it's (a) electrical, and a lot of dodgy dealership mechanics hate electrical; and (b) an "old car" that they can't simply plug into the DIS/MoDiC and have OBDII sensors (hopefully) tell them what part(s) to replace.