Yes, you can. TDI VW's are super reliable, but the newer ones (2005+, iirc) can have injection pump issues. My 2000 TDI Jetta just rolled over 250k miles without any real problems. I love my little commuter, its quick and drives awesome in the mountains. The turbo diesel will cruise right over Vail and Eisenhower Pass like they're not even there.
We love the mileage and reliability of the TDI so much that we just picked up a 2nd TDI Jetta for my wife. It needs some work, but it was cheap and still averages 46 mpg.
I am a huge fan of German engineering, I would love to own a Mercedes or Audi with a turbo diesel.
Is the Passat available in AWD with a TDI? If so, that would be an awesome car.