I found this on the web, and we all know the internet wouldn't lie to us
Looks like I was a little off, probably because I didn't factor in any rolling resistance.
"Among commercially available 1984 model street cars, the most aerodynamically efficient was the Audi 5000S, with a Cd of 0.33. The Chevrolet Corvette was close behind with a Cd of 0.34. Most other street models have approximate values of 0.40 (my wife's Chevrolet Chevette, I have discovered, is at the high end of the spectrum with 0.45)."
Mine's an '82, but you get the gist of its aero properties. They're bad. Nosecone maybe??