DON'T GET A HYUNDAI ELANTRA!!! Its wrong wheel drive man.
What she should get is a Honda S2000. Make sure she gets a couple sets of rims so when she takes it to the track she can swap them out.
OK for real...
Chevy Cobalt (reliable and with cruze coming prices are really cheap)
Nissan Sentra (not as nice looking as older model but cheap as many pass it over now)
Pontiac G6 (can get real cheap now but it a little larger)
Ford Focus (good all round car to add to the mix)
Chevy Cobalt? Are you serious?! That car is a colossal piece of crap. Very unreliable. I work for a rental company and we've had nothing but problems with them. The suspension, sensors, and climate controls are usually the first to go. Typically at 30k kilometers. 50,000km and they're done like dinner. They even feel cheap. Cruze I can't speak for.
I've driven a lot of cars in this class. Here are my top pics.
-Ford Focus
-Honda Civic
-Mazda 3
-Hyundai Sonata
If you're looking for something cheaper, the Kia Forte actually isn't that bad a car.
Guys, guys, let's not fight. Instead, let's discuss something we can agree on: don't consider the G6! The engine is a peach, but the interior is shite and the electric steering is prone to failure. My buddy had one (don't remember the year) and he was replacing the electric steering unit every year.
Cheap rental cars that are beat on do not equal real world results.
I have worked on a ton of them and they have been very reliable cars. Even edmunds and owners give them high ratings in terms of relability.
http://www.edmunds.com/used/2007/chevrolet/cobalt/100759439/reliability.html
Funny you turn you nose up at the Cobalt but recomend a mazda 3? Really? Even owners of Mazda 3's that love them admit they have plenty of issues.
Mazda 3 is UNBELIEVABLY better and more expensive.
More expensive = better? Who would'a thunk!
Still, Mazda 3 is a nice choice, and is seconded by me.
Elantra is a good choice. It's like the Corolla. Boring car but cheap to maintain and very reliable.