Pep Boys sells an Accutron (top of the line but I don't remember the stock number) for $180 or $200. Autozone sells the same for $280. It shows you 4 lines of code and is pretty good for reading trouble codes. I have used it on a 325i and a Chevy truck. The scanner comes with a trouble code program that is not much more than the 4 line readout though, but if you can't figure out what the code REALLY means go the dealer. My local dealer was very helpful in indicating what the code really meant, and I fixed the problem for nothing, so the code reader paid for itself in the 1st use.