This is all you need to get full access to the VAG-COM software and functionality from any computer it is installed on. No licensing required - the key is in the hardware.
As well as fault finding, this can be used to log performance statistics as you drive - obviously with a passenger operating the computer

Cost new is $330 from Ross-Tech, plus [potentially] import duty and tax
Selling mine for £130. Perfect condition, and an excellent tool
For sale, as I no longer have a late VW/Audi to use it on
PM me for more details
Cheers
Andy