Yo G! I done a CFD...and my computer doesn't want to leave sleep mode just as it converges on an answer
It did it twice, so I'll take it as a sign that the automotive gods don't want you to have a certain knowledge...
This model is 2 m wide (racing limit) by 4.2 m long, S = 1.594 mē. 335 section rear tires, wheel wells, no mirrors or suface details. By thickness I mean the height of the body - as if you were looking at a wing from the side view. I put a 2" radius on this body 'cause it was quick.
fwiw, it was at Cx 0.357 at 250 IT, and Cz 0.101 (about 100 lb of lift total). A 'tunnel' between the rear wheels will kill some lift, and 11° is too much for the rear taper - although a small spoiler will help.
I think small spoilers on production cars are mostly for style. the 5 part racecar body is to provide as much clean air to the rear wing as possible...although I can't say what it does for drag (minus the wing).
I hope you enjoy the pretty picture...it will now be my avatar
