Nothing.
The car has been flawless from day one. The car boasts averages of well over fifty miles per gallon combined motorway and around town. I can honestly say that I have never seen it achieve less than 28.9 miles per gallon. The car has superb handling and acceleration and the sports seats are very comfortable. The car came with a solid set of speakers (though disappointing head unit), most of which I did not have to upgrade. Even with a 1000 watt sub-woofer in the back the car hasn't rattled. Build quality rivals that of my old BMW. Though it's not a BMW it's an excellent run about. I'd say £15,000 well spent.
I completely agree with you! The Golf in my opinion is way better than the Audi A3.