Depending on how much your car sits in the sun, you may already have this happening to your headlights. They get a nasty looking haze over them. Luckily, Meguiars makes a great product to spiffy them up real quick. I know its not an Aveo, but this happens to all headlights that are plastic.
So, first things first, go get yourself a bottle of PlastX (or whatever the local auto parts store has for sale). I've only used Meguiars, and can say it works great.
First you clean the headlight. I just took a wet rag and went over it real quick. Then, you just put some of the polishing compound on your rag or what not. I just used a paper towel and it worked fine. You just rub it in and it clears right up.
Here is what I started with. Doesn't look as bad as some I've seen, but its not pretty either...
Here is halfway done with the headlight.
And, here we have the completed headlight. Looks way better.
And here is a comparison picture just to see the drastic difference for a few minutes of work. I think with taking pictures this only took about 10 minutes per headlight.