Bought this jobbie on e-bay. Plugs into OBD port. Engine, trans, ABS, air bags.
Most importantly it can clear ABS codes, which on at least the several early 2000's I have fixed, can be the sole problem.
Also they give you a book of the VagCom codes which provides more info than OBD codes. Not loads of info, just other things that can be throwing the code. E.g., If you have a VW you have probably had a coolant temp sensor code. It can also be the thermostat at fault which OBD does not reference.
http://www.ebay.com/itm/VAG-Scanner-Code-Reader-Airbag-Reset-SRS-ABS-Scan-Tool-COM-CAN-BUS-K-Line-Device-/151297642485?hash=item233a0acff5&item=151297642485&vxp=mtr