In 1963,Walter Korff commented that stylists would have a great degree of latitude with cars down to Cd 0.20.
In 1969,R.G.S.White,at MIRA,commented that Cd 0.25 could be achieved with virtually all contemporary shapes.
A few years further on the head of Ferrari said the same thing.
In the mid-80s,Wolf Hucho also spoke of the creative license availed to stylists,when talking about vehicles with around Cd 0.25.
To venture into really low drag,either half-bodies or wing-type shapes would be required,as only these forms guarantee attached flow over the entire length of the vehicle.
Length becomes an issue,just as in the 1930s with Fachsenfeld's and Kamm's K-form car.
Here,Hucho suggested we revisit the 1930's 'extensible' tail,which would only be deployed on the highway.