there was a b7 on the floor of bill jacobs in naper for awhile, my dad would try to get to take if for a test drive when he had his 740ils in for service... thing was ballerific
the cool part on that Alpina is how you inflate the tires. There is the schrader valve inside the center cap and one of the spokes of the wheel is hollow to let the air from the hub area to the tire.... that kind of engineering is just sick!
also im not 100%, but i think the supercharger is a rotrex