So got the Cobalt SS (2009 w/LSD) with 21000 miles on it about 2 weeks ago.
So far I have done a lot too it in that time:
shaved emblems off of trunk
k&n short ram intake
megan racing catless downpipe
muffler delete (american muffler shop in fayetteville)
mpx intercooler
depo black projector headlights
injen upper charge piping
replaced bowtie on front with SS badge
and finally had M-Dub from Raleigh tune it (boosting around 22lbs with peak at 25lbs) Cobalt SS Network - View Profile: M-Dub
She is so sick now and i'm very happy with her. Proud that I was able to afford all the parts and make her my own. Still have some eibach sportlines I will be throwin on this week sometime and swapping out the spark plugs this week with AC Delco 41108s.

Here's some pics:

 

Veyr clean. Nice car.

 

Looks good, you should come out to the weekend meets in K-mart parkinglot.