well it is getting close to the 10 years/100k km point where most cars begin needing occasional repairs and people who don't care much about cars just get a new one, at least here (lots of VWs around).
That'd be a reason for selling, but she shouldn't except 0 problems when buying used because it's at the point where problems begin.
Might be she're buying someone else's headaches.
I'd never buy a used car with an auto tranny, usually there's some issue that pushed the owner to sell.
The fact that he paid lots of $$$$ to replace it and is now selling anyway is weird and would make me suspicious.
I don't know specifics about the car, but I know somebody who has always had those and kept them for more than 10 years every time and had no problems whatsoever, but they were manuals.
I like VWs and never had problems with them but I can say I'd never buy one used, an old polo that was way past 10 years and had seen a lot of commuting had a door that almost fell off (due to slamming), the centralized unlocking system that broke (you had to insert the key in each door to open it or enter the car and open the other one from inside), the belt that had to be replaced, the clutch was worn. It was almost to the point where it would not be able to pass the trial without spending lots of money on it. On another one the transmission began to make crunching noises when changing gears.
Also the audi a4 seats are uncomfortable.
I agree with Jimzz except for the VW group bashing. Those cars are made for the European market, no need to hate.
The Dekra report says the Audi A4 is a pretty good used car though:
http://www.focus.de/auto/gebrauchtw...-gebrauchtwagen-aller-klassen_aid_923560.html