Yep, seen it race a couple of times. Awsome.
The XJR-12D also has a two tier rear wing. It raced in 1993 Daytona 24Hr.
Was meant to race at LM but was withdrawn due to unfavourable regs against the 3.5l cars.
http://gto-racing.nexenservices.com/...guarXJR12D.htm