Purchase A6?

Hi guys, I usually stop at the Mercedes W203 fraction. Now, however, there has been a discussion in the family council, which deals with the purchase of an Audi A6. This is an Audi A6 Quattro Combi with 170 hp & 2.4L Maschiene of the year February 2003 with Autom. Gearbox & approx. 29000 KM. Can you get some helpful information about this, as for example what I have to pay attention to, there is information about parts that are particularly prone to errors or repairs. , how much fuel runs on this mashie about through the Agregat, etc. I am grateful for any answer or tip. The purchase should decide by next Tuesday. So over with your opinion whether positive or negative. Thanks already Sesse