I'm going to have to disagree with everyone here who says the M5 will own the SS all day long.
http://www.insideline.com/cadillac/c...-benz-c63.html
According to this article, the M5 ran a 12.8 quarter mile. 'nhra stocker' pulled a 12.63 1/4 adjusted at 12.43 for DA... on the contrary, this shows the SS running over the M5.