Sorry I thought you had 4.6 in your post.
The site shows me the Model S Performance is $88,570 in which that price includes a $7,500 tax credit.
Click on the cash button.
Model S Design Studio | Tesla Motors
So the Model S Performance price is actually $96, 070, which is still cheaper and quicker 0-60 then the 911 Carrera S 0-60 of 4.3s at $98,900. I'd still take the 911 Carrera S over the Tesla Model S, but that my take on those two. If I was going to buy an American car in this price range, it would be the new Corvette Stingray.