I have had this car for a little over a year now, and I have had nothing go wrong.
My Sentra is driven roughly 70 highway miles per day, and I spend no more than $25 a week on gas (at 2.43/gallon).
My car is a 5speed which definately helps improve performance. I added a K&N air filter, replacing the factory one, and I would recommend this to all Sentra owners. The filter costs around $40-50. It adds noticeable power, increases gas mileage, and also alters the engine sound, giving it a surprisingly sporty tone. I also put 195/60/14 tires on my car, replacing narrower rubber that the car comes with originally. The wider tire give the car much tighter handling, and also made a huge difference this past winter when the roads were less than perfect.
Once in a while I find a piece of interior trim coming loose, but everything always snaps back into its place.
I wrote this review back in 2005, and I still own the same car. I recently hit the 100,000 mile mark, and still have not had any major issues! My front brakes were making noise, and I chose to 'ignore it' a little too long. Due to my laziness, I needed to replace two rotors, and the right caliper assembly. I also replaced the pads. What would have been a simple brake job ended up costing me over $500. I blame myself, and not the car. Other than this, I have not had to replace anything other than oil, belts, hoses, and tires. (normal ware). Currently riding on Dunlop Sport A2 Plus's. I love them.
This car continues to impress me, especially on the highway where I do almost 90% of my driving. In 2005, $25 filled my gas tank. Now in 2008 it's more like $50. :- (It was interesting to find this review, I forgot all about it! I wouldn't change anything, and I plan on holding on to this car until it stops running.