Let's see if I can get something over from Photo-Bucket
You can see the fineness ratio with the lowest Cd.
Hucho puts it at 2.5:1,and in mirror-image ground reflection creates a vehicle body with an 'effective' length-to-height ratio of 5:1 and Cd 0.08.
By adding wheels the Cd goes up to 0.12-0.13.
Wheel fairings can bring that down as with the 1987 GM Sunraycer/1993 HONDA Dream 2.
This is the premise for the Aerodynamic Streamlining Template.