how about using our KERS or ERS to power a 'fan-car ' type (or other type) supplementary downforce system ??
(used at lower speeds to give good downforce throughout the lap)
this would be beneficial to lap time, and to the quality of racing
(by better and more legitimately realising the goals of exhaust blowing/not blowing and DDRS/notDDRS etc)
under braking it would allow increased energy recovery, and mostly use live (not stored) energy recovery
'fan-cars' developed large downforce at all speeds using less fan power than KERS and far less than ERS
what's not to like ? - it could even justified as green and road-relevant (to Ferrari etc buyers)
the rules ? .... they are made to be evolved - that's official