[lunarhighway]

won't a larger tail actually stabilise the car in crosswind conditions? i think i read this in an article about the mercedes 111 (i think) where a fin was added for high speed runs. the fin at the rear actually enlarges side surface (without adding frontal area or much drag) so when the wind pushes against the side of the vehicle the rear will be pushed out more, and the car will "steer" itself into the wind countering the effect of the corsswind.
so a longer tail should be somewhat similar to a tailfin