.42 for the Countach, but I believe that is without the wheel flares and rear wing.
Those probably* brought it closer to .50 or more.
Here is an original tuft test without the wheel flares and wing. Also, note the intakes along the sides were flush, unlike the later versions.
later version :
My favorite bit on that car was the aircraft inspired NACA duct .
* new lazy wordage : " prolly, or proly"