I currently own a 2011 Elantra that I bought new. As for gas mileage, these cars DO NOT get 29 miles in the city per gallon. It's more like 24 and I don't drive hard or fast at all. I do however average between 38-40mpg on the highway for long trips and I'm usually driving between 70-75mph.
Other than mileage, I really like the car. It has a ton of space for its size. Great back seats and a nice big trunk. I also got the navigation system and back up camera.
The ride is smooth and the interior is very nice for a car in this price range. Depreciation is almost non-existant too. I checked KBB and currently private party sales is around 16-17k with 20k miles on the odometer and I bought this car round $18.5k. Granted these cars are in much higher demand than when I got it.
It's cheap to insure and its cheap to maintain. My current dealer offers free oil changes if I get my standard maintenance done at the dealer. My 15k service was like $360 and I didn't spend squat before that.
I really like the 5 year bumper to bumper warranty too.
In short, I would definitely recommend this car for highway driving. But if you do a lot of city driving, the mileage leaves a lot to be desired vs other cars.