A scary, scary used car buy, especially a 2003-2005 model. I've heard horror stories of owners needing a complete suspension replacement costing in excess of $7500 - likely half the value you'd pay to buy the vehicle in the first place. Unless you have absolutely convinced yourself that nothing else will do, there are a lot of other capable 4x4's out there that have a much better reliability rating, like the 2003+ Toyota 4Runner or Nissan Pathfinder.
That being said, if I had the dough to pick up a 2009 V6 TDI, it is a capable, attractive, solid vehicle. Kind of like a Range Rover, but cheaper!