RE: VAG-Com
 

Code readers just read codes and clear them. A vagcom can not only read codes andclear them but also allow you to log information for better troubleshooting or my fav part which is change attributes about the car. For example: My windows now all roll down if I hold the unlock button, and if I hold the lock button they all roll up now. This is not a feature offered in the us on the B5 A4.