These are great cars but there are a couple of things you should be aware of. 2012 is smack in the middle of VAG's emissions cheating and the car has most likely had the software update, the update has a significantly detrimental effect on the cars reliability and durability. Hugely expensive repairs to EGR valve, DPF and fuel system are very common. It's relatively easy and not too expensive to have the original software reinstalled and its perfectly legal as well but will only be done by an independent car tuner

You can check if the car has had the emissions update by entering the VIN on Audi's web site, search for "emissions update".