In SAE Paper 700035 by Karl E.Ludvigsen a 1961 Panhard D.B.coupe with enclosed rear wheels is reported at Cd 0.15 in model,Cd 0.18 in full-scale.
For around 1963 a Panhard C.D.,by Deutsch and Romani is reported at Cd 0.15 with wheel fairings.With 60 bhp the car was capable of 127 mph.
Marcel Hubert,associate of Romani worked on the C.D. and went on to become an automotive aerodynamic specialist,responsible for the 1963 Alpine M63 which also showed Cd 0.15.
Amazing when you consider Austin Healeys,M.G.s,Triumphs,and Corvettes of that period.