The Sentra is my first car, and I'm happy to report that my experience has been excellent.
Don't let this car's small stature fool you--it feels more expensive than it actually is. The doors close with a reassuring thud, and the car has a general lack of squeaks and rattles--it has withstood three years of Minnesota potholes. Nissan did not skimp on interior materials--the door trim and fabrics are well-matched, and still feel like new. My only suggestion for improvement would be more thigh support in the seats.
Performance is reasonable if not outstanding for a car of this price range. The engine has plenty of grunt around town, but buyers may wish to opt for a manual transmission to wring the most performance out of the car. That said, the automatic transmission shifts smoothly, and the engine revs and idles quietly. The car tracks well on the highway, and handles nicely. You won't mistake it for a sports car, but, when driven aggressively, it is respectable.
My dealer experience has been excellent--I highly recommend Feldmann Imports to anyone in the Minneapolis area!
The gas mileage is phenomenal-i-taverages about 35mpg under my lead foot.
I would highly recommend the Sentra to anyone looking for a low-priced, high-quality car. Also, Nissan makes a more powerful (albeit more expensive and less fuel-efficient) version of the car for those who need a little more performance.