Having read this article (about F1) on another post:-
http://www.fia.com/resources/documents/ ... mework.pdf
I'm surprised that the people at the AcO haven't done something similar for their top prototype category, to limit expenditure/developement on areas that don't have a direct relevance to road vehicles (specifically the aero side of the cars)
i.e:
Mandate "spec" underfloor tunnels
change the upper body rules so the cars resemble supercars rather than single seaters with covered wheels -including windscreens of a minimum size and radius of curvature.
This would also allow the cars to have styling features from their road-going stable-mates.
Also rather than being shrink-wrapped, the bodywork would be much larger -allowing ample room for the power unit -HERS, KERS etc
Something a bit like this:-
