I’m betting it’s from the 1999 Cadillac Evoq concept car...The image seems to have a similar silhouette and it did have a retractable top.

Stability under varying temperatures and atmospheric pressures, as well as being non-magnetic are the biggest reasons.

Agreed, I came down here to post the same thing...The only real info on this car that exists is a Racecar Engineering article and a blurb on Mulsanne’s Corner. Please, please tell me there are more pics!

Fees for extra leg room...I’m tall, so for me extra leg room is not a luxury, it’s a necessity. I’m so tall that I can’t sit in the seats on Southwest because my knees touch the seat in front of me before my butt makes it into the seat. I propose that anyone 6’4’ and above should be able to select an extra leg room…