Did you also consider Toyota Prius?
If your wife can accept less comfortable driving position, less passenger room, less cargo space, and less max load (835 lb. Passat can take about 1100 lb) than Passat,
Prius is another good candidate.

Fueleconomy.gov annual fuel cost (15000 miles/year. 45% highway)

Prius: $475
Corolla: $657
VW New Beetle GL 1.9 TDI: $533


Prius has safety add-on's that Passat has.
ESP, Brake Assist, window airbag.

__________________
1992 300D 2.5 turbo diesel. 319 k miles.
124.128 chassis, 602.962 engine, 722.418 tranny.