I had this car as a rental for about two weeks while my 2001 Camry was in the shop, and while I was car shopping because it had been totaled for a second time.
There were really no bad things about the Elantra, so I will start there.
First, the trunk was small compared to my 2001 Camry. A footlocker BARELY fit in it.
The paint was very fragile on this car. It was thin and scratched easily, particularly on the bottom of the trunk lid and on the door handles. The car was black, so maybe this had something to do with it (maybe the red or blue ones are better).
The car blew in the wind easily, and, the more weight that was in it, the more it swayed on the highway.
The brakes, although better than my Camry, could not stop a train.
The car fared much better in regards to the engine. The car was not fast, but it wasn't slow. It was faster than my 2001 Camry, that much is certain. The Elantra also had EXCELLENT gas mileage, with the lowest figure being 29 MPG and the highest being 38 MPG.
The seats are above average. They were very comfortable and sculpted well. For a car, they were as close as one could get to sitting in a La-Z-Boy. But, the material was too easily dirtied. Headroom and legroom abound in all seats, but I question how comfortable it would be for three people in the back seat for longer than several minutes.
The controls were logically laid out as far as the radio is concerned. The Sirius/XM Satellite Radio received signal very well. The center stack had to bright of a blue backlight and the text on the screen was too dim to read against it at night. This is similar to a 2010 Hyundai Accent I rented a few months ago.
The air conditioning was very efficient, but smelled of brussels sprouts when it was on full blast.
In conclusion, the Elantra is an excellent car for what it is. I understand why it is Hyundai's mainstream model, and it is because Hyundai designed their cars so people will want them. I would consider this car in the future.