The Jetta TDI is a great car. My family needs booted me out of my beloved compact pickup, but this is a worthy replacement. If you're hauling children only in back, definitely remove and store the rear head rests...at least remove the middle (of three) for better vision when backing up.
The classic VW "open all power windows at once" when the door lock key is held in the open position. When carrying kidlets it gives you a chance the air out the car quick before imprisoning the kiddies in the baby seats.
All the TDI VW's should come with the MPG dash guages that Toyota Prius' have in their dashboard. I retro'd a 'scan guage' (OBD II tool with MPG guage in it) from thinkgeek.com to make up for it. It help's me locate each gear's most efficient rpm, which changes with incline and load. I get 49 mpg at 74 mph :).