Nobody noticed this mockup's wheels are nearly identical to those of a 1992 Ford Escort RS Cosworth, which was also designed by Steve Harper / SHADO.
Apparently Steve Harper's SHADO company was active in 1986-1987, 1993-2000 and 2007-present, so this 1992 proposal should be credited to Steve Harper only but it's all quite confusing anyway.
Steve Harper / SHADO's website is well worth a visit as it is packed with sketches and mockups of rejected designs, which is a real treasure trove for puzzlers like us !