Essential for any VW/Audi owner, the VAG-COM program allows you to perform the same advanced diagnostics as your dealer. That's why many dealer techs use the same tool instead of the much costlier VW version!
Be sure to check your laptop for the correct interface (serial or USB) before ordering. Please email if you are not sure which one you have, especially since many new laptops do not include serial ports. Older cars (pre-1996) will require the optional 2x2 adapter.