Wheel bearings on front right wheel failed and needed to be replaced at approximately 70,000mi.
Brake rotors suffered premature warp that necessitated replacement (couldn't be machined) @ ~ 75,000mi.
Passenger seat belt tensioner jammed and needed to be replaced. ~ 45,000mi.
Ball joints have begun to pop when steering is in full right or left lock, yet to be repaired. Started ~ 80,000 miles.
This car has been a daily commuter that sees between 70-100mi daily. I've owned it for about three years, and for the most part, it has proven to be very reliable.
In terms of engine and transmission, both perform as well as they did when I bought the car. The 2.0 16v DOHC engine is solid.
The auto box, though, can be kind of annoying because it sometimes hesitates when you really want it to shift. I test drove an Elantra with the standard 5-speed, and that's the one to go for. Though in reality it's not much faster than the auto box, it feels so much better and it lets you play with the bountiful revs that the car can deliver with it's CVVT system.
The other reason to avoid the auto box is because at highway speeds (65-75mph) it'll be pulling at ~3k RPM in 4th gear. It can get tedious.
The Elantra has a pretty stiff suspension, which is a plus in my book as it makes it feel more lively and it takes speed bumps pretty well.
Interior quality is starting to show. The fabric on the center console is already wearing thin, and the rattles on rough roads seem to get worse as the car ages. Some of the plastic is very thin, and some of it on the B pillar cracked for no apparent reason.
But, all of that aside, I like it and the most important stuff, the drive train, is holding up well. I'd give the Elantra a thumbs up to anyone looking for a cheap commuter.