I will say, the idler pulley does just go again once you've had it done. Doesn't seem to cause any issues though!

Depending on the age you are looking at, 320d is ok, 330d is a machine! Although the bills could be substantially more expensive!

In response to above, passat is a well built motor, dull to drive though by comparison and you would need the 2.0 to come close in the pace stakes.

Any diesel seems to benefit from a decent map.