Does it come with stock exhaust or some kind of upgraded exhaust. I was thinking about trying out the gm performance performance cat back exhaust but I am not sure if I already have something along that line.

 

I'd say it is as much of a performance exhaust that GM can get away with while still meeting noise emission requirements.

The cat back is better, but for the price, I think there are better exhausts on the market. I'm looking at the Hahn 3" Cat Back.

 

The Hahn catback requires a different adapter to attach to the cat than the 05-07 balt - so unless GM is now making a performance part catback for the 08, you will need to modify it to fit - besides isnt the performance catback for the 05-07 a 2.5"? There would be no upgrade for pipe size there, and the muffler would probably be more constrictive.

Go with Hahn's if you want a performance exhaust, otherwise the stock one sounds GREAT and looks good too.