Let's just say I've used my "certified used" warranty a little bit in the last year (4 times). So, I go back yesterday because the front driver speaker quit working & they had to fix it. I asked how long I have before my bumper to bumper warranty runs out, and they said July 2012! The dealer gave me 3 years bumper to bumper warranty on my Cobalt (I thought it was going to be just two). Man, they must have been desperate to get rid of this thing when I bought it in 2009.
Only downside is any mods are purely cosmetic. Not doing anything that could void my warranty. Small price to pay to have a paid-off car before the end of the warranty period.
I bought mine in july of 09 and sould be paid off in july of '11 of sooner. I haven't really done mods because my extra $ goes to paying it off. That way I can trade for an 08+ SS....if I dont find anything I like more.