I have also seen a double spoiler used to increase downforce, with no real regard to Cd. Hucho shows an example of a car with no spoiler, a car with a low spoiler, and a car with a low and really high spoiler. The low spoiler (like one on a Gen1 Prius) lowers the Cd, but with the really high one, it increases the Cd and downforce considerably. I like the looks of the spoiler on the car, but knowing that it actually helps the Cd is what puts a smile on my face!
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