I take it you're asking about the 1.9TDI quattro in the other post: especially with the quattro's, check there's no "shunting" from the drivetrain as you pull off and see how bad the rust is on the arches to see if it's a treatable and how much it woudl cost to sort out.
Otherwise that looks like a very decent car and factory in the high mileage against how worn the suspension feels and that it's had regular oil changes, etc.
Definitely a good spec to go for unless you're a real power junky, but remapped to 160-bhp easilly, it's a decent mix of less weight and better economy, I'd seriously be considering if I was buying mine again now: I got sucked in by the V6 purr and smoothness compared to the 4-pot 1.9TDI, but the fuel economy difference is significant and the outright pace isn't that different: certainly if you're comparing a remapped 1.9TDI vs an unmapped 2.5TDI.... the 2.5TDI's don;t normally map very well, certainly compared to the 1.9TDI's (the 130TDI in the quattro being the best for mapping).