We just sold our '02 Jetta TDI. It got great mileage and I believe the diesel engine is rock solid. There was quite a bit of incidental maintenance (things breaking, wearing out).

We consistently got 35+ mpg without really trying - this is with an automatic. On longer trips we weould see 40+ mpg.

Sold it (for a great price as they are not available in the '07 VW's) and got a Camry hybrid for our larger family (we just added our third son 1 month ago and the backseat was more than a bit cramped with 2 kids plus a big carseat).

I liked the sound of the diesel too...

Scott