Ebay ones don't work, look cheap then they are cheap and too good to be true, go to ilexa.co.uk and buy VCDS, it works brilliantly across all VAG cars, it allows you to do lots of things other than read codes, I adjusted the diff setting on our Fabia VRS for a track day and then returned the settings afterwards.
Well worth the investment and you can let people know that you have it and make a little money back off it by scanning your mates cars too.
Get what you pay for
