I have a practically new Magnaflow 15053 for sale. Had it on the car for a few hundred miles.
Decided to go a different direction with a catback.
Just paid $1,600...would like to get $1,100, but any reasonable offer entertained.
This is the exhaust listed for a ZL1 because of the quad tips. It fit perfect on my SS1LE.
http://www.magnaflow.com/products?partNumber=15053