Yup, that is one bad Buick. It'* funny how many forums I've seen that show up on. First saw it on Turbobuick.com (one of my other hangouts on the 'net) a little over a week ago. Pretty much the same reactions everywhere else I've seen it since.
You're right, full race car, not street legal. Twin Turbo V8, no longer a 6 cyl. I'd really like to see an under-hood shot of that setup. It'* just so over-the-top, certainly isn't gonna sneak up on anyone.