Im new to the forum i just bought yesterday a 2010 Chevy Cobalt LT from carmax I paid about 13,250 i think was total out the door. It has 34,000 miles on it was from a fleet company i guess is what they told me but its very clean inside and out love the car. Being a Chevy Owner from a S-10 and a silverado i think my eyes one of the better cars Chevy has made. I have a couple of ideas what i want to do to it it will all come in time.
I just went and got a muffler shop made exhaust.
2.5inch
Cost me $75 for piping and install.
Haven't had any problems with it at all. It's cheap but its good sounds great.
If you want to save money just go to the shop.
Most exhaust will cost you $250 or more.
The exhaust I like the most the one I wish I had is the gmpp exhaust you'll only find used ones and you'll have to find someone online selling it.
Try ebay or another cobalt site, hell check g5 forums.