Jack, this was a one-of-kind transport for '50s MB race cars. It was designed to transport the cars very quickly between races. The front body shell is derived from the old Ponton--check out the doors and windshield. The chassis is a modified 300SL spaceframe with a 300SL motor.
The car you see in the pics is a factory reproduction that they finished building just last year, the original having been destroyed some time ago.
1995 MB E320 Wagon
2001 BMW 530i
2007 MINI Cooper S (!)