Here's something to think about:

Remember when Bob Lutz mentioned that the XLR's plastic body panels were temporary, and that it would be restyled with steel panels to better compete with it's competitors?

 

If I had to take a 2nd guess how about a kappa caddy for the us? The look of the car says mid-engine. In fact one of the sketches in the top left of the picture looks like a fiero. Can anyone blow up the background pictures?

 

The image in the e-mail was not sent by the GM design group. It was sent by a GM marketing group.

There is no way in hell the marketing group called up the design group and said "send us a pic from your top-secret studio so we can send it out via e-mail". Get outa here. There is just no way that it could have even been leaked and then gotten approval to be sent out to hundreds of thousands via the e-mail.

The image is probably just a stock image they had laying around, it has probably been used for other things as well.

Have faith, but remain realistic.