Haven't come across many 2011 much less a SS. Going to be hard, but i've being search for a 2012 myself. My daily searches include: http://www.autotempest.com/
Searches ebay, cars.com and autotrader.com
and this website.
Check them all in the day and in the night.
I used to check 6speedonline.com
If anyone has any others that ppl post on let us know.