This is what i recieved in my locost "yahoo" list.
" The typical modern automobile achieves a drag coefficient of between 0.30
and 0.35. SUVs, with their flatter shapes, typically achieve a Cd of 0.35–0.45.
Notably, certain cars can achieve figures of 0.25-0.30, although sometimes designers deliberately increase drag in order to reduce lift."
2.1 - a smooth brick
0.9 - a typical bicycle plus cyclist
0.7 to 1.1 - typical... Formula 1 car (downforce settings change for each circuit)
0.7 - Caterham Seven
0.6 - a typical truck
0.57 - Hummer H2, 2003
over 0.5 - Dodge Viper
0.44 - Toyota Truck, 1990-1995
0.38 - Volkswagen Beetle
0.38 - Mazda Miata, 1989
0.36 - Honda Civic, 2001
0.34 - Chevrolet Corvette Z06, 2006
0.33 - Mazda RX-7 FC3C, 1987-91
0.29 - Honda CRX HF 1988
0.26 - Toyota Prius, 2004
0.25 - Honda Insight, 1999
0.195 - General Motors EV1, 1996
0.137 - Ford Probe V prototype, 1985
I went to: and none of their "7s" had the body mounted "wing" type front fenders but, had the suspension mounted "cap" [?] fenders. I know that the drag difference would be quite a bit between the two fender types. I went back to the image list in the Wikipedia article and it showed a correct Caterham 7 with the capped fenders, no top, with a roll bar so, the numbers ought to be useful enough for Locosts.