For a road-going car, I think I would prefer Trond Bråthen's air suspension modification. It is very neat to be able to control ground clearance from the driver's seat. On the AR P4 you have to stop and crawl under to adjust

A cheaper way to get a more impressive engine compartment, would be if MMC could use the Cosworth plenum inlet manifold. It would require no other modifications except possibly a remap of the ECU.
Harald