[aerohead]

Originally Posted by Big time

Bugatti Veyron Cd 0.41 normal 0.36 lowered and preventing rear spoiler from deploying
Bugatti Veyron - Wikipedia, the free encyclopedia

Hennessey Venom GT 0.43 rear wing raised, 0.36 rear wing down
First Look at the New Hennessey Venom GT - Photos and Just-Released Details - Road & Track

Koenigsegg One:1 0.45-0.50
Koenigsegg One:1

They don't make THAT much downforce. At least not compared to all out racecars.
Are high Cd figures from cooling drag?

At these velocities,directional stability and safety are paramount to the manufacturers.They want their customers to live to buy another car.
They may do detail optimization to trim drag as long as it does not impact stability/safety.
Plan-views of these cars reveal drag-unfriendly profiles.