Ditto....
Body has no real effect at low speed.... But has a bigger effect than you setup will at high speed.
Mid speed is a combination...
As fas as your body goes, try using an alfa and a stratus back to back. The alfa has more downforce but both have even balance.
I find the alfa feels good to drive with good laptimes, mazda goes quicker but a little less consistent, and stratus feels like it has no steering but produces good race times.