For around $200 ($190 with free shipping to be more exact) you can get a set of very good KYB GR2 struts and shocks (change them all around front and back) and you can do it in about 2-3 hours of your time if you have access to a garage with a couple of jacks and 4 jack stands. You can rent spring compression tools at any local auto parts store... autozone takes the deposit on your credit/debit card in the amount of the price of them (around 50 bucks) and then gives you your money back when you bring it back in the same condition.

Here's a link of the set that I have (even same seller I think):

http://cgi.ebay.com/ebaymotors/KYB-4-GR ... 500wt_1182

You will definitely feel the improvement over your stock shocks/struts and you will learn a little more about your Aveo... It's very easy and self explanatory if you're at least somewhat mechanically inclined.

They're alway two-way shocks/struts as opposing one-way that you have in there from the factory.