best down-force body?

[c3racing0082]

@ what speed does downforce play a role?

 

[BUDDHA]

I cut the ass of the car out.
Under the trunk line from tail light to tail light.

but you have to watch out for how much you take off-
there is a limit to what you can cut off according to ROAR rules.
from the 2002 rule book
3-11 touring cars may have a 2" diameter (50mm) hole.for the front windsheild.
3-12 including taillights and bumber must remain intact.it is recommended that some portion of the cut line remain visible to help speed technical inspection.