I own a 1989 Nissan Sentra for about 2 years now. I have put on around 20000 miles on it since and the current odometer stands at 130000. I havent had any major complaints with the car which has always taken me from Point A to Point B without any fuss and minimum maintainance. I think I have spent around $1000 on it since I purchased it for $1000.
Appearance and Space: The looks of this car are definetly not modern, but I am writing this review also in the hope that people planning to buy a newer Sentra might find it useful as well. The paint is of pretty good quality and even after 15 years out of which it has been parked outside for atleast the 2 I have owned it and 7 before that when my friend owned it there arent any major blemishes/rust marks. I live in California so it might be different where it snows a lot. The car can easliy accomodate 4 and squeeze in 5 for a couple of hours without any discomfort. The driving position is low and being 6 that has been my biggest complaint with the car. My knees start complaining on long drives. I also drove a newer model which seems to be better regarding this. Trunk space is adequate for 2 large suitcases and a couple of handbags.
Driving Experience: Nissan engines are considered to be one of the best ever made and this car is no exception. I have an automatic transmission and even so the car has never complained too much at red light pick ups, while overtaking other cars on a freeway (as long as you dont become too ambitious by deciding to take on 6 cylinder vehicles), or while negotiating hills. Lately the car has been giving some problems in its transmission while moving on hills (it doesnt shift properly), but after 130k miles an investment of $500 in a transmission is not unusual. Mileage is excellent : 35 mpg highway, 25 mpg city.
Maintainance: The best thing about this car for me as a graduate student has been its almost zero maintainance. All I have done is regular oil/filter changes and had to get a new radiator for $300 beacuse the previous owner was driving it without a coolant for months!!
Overall, it has been a very reliable (Ive driven it on some long 1000 mile trips), maintainance free car for me. For people looking to buy a new Sentra, its worth the investment if you plan to keep it for a long long time to come. But its definitely not a car, which is going to draw chics, or give you the ooh aahs on the road.