HI SPEED BODY.
I know people have been going to a hi downforce body for land speed records.
having run on the velodrome track I have found that the hi down force bodys will scrub speed because the hight downforce causes the car to be pressed down to the track to much. you can hear the pressure on the tires and see the slow speeds. its like adding 5 lbs of weigh or more.
The trick to high speed is not down force but aerodynamics that allow the body to flow thru the air and not push the car down excessively.
In velo oval racing a blunt nose would be preferrable rather than a pointed nose. and a pull in hips rarther than a wider rear. also a small wing, remember the down force exponential will increase on the small wing especially at 50 mph and above.
I have some ideas I will be applying to my velo body, blunt nose,with rear bumber on , rear under the trunk valence, areo wind channel above the battery tray, and a wing with small side plates. We all continue search for that areo advantage at hi speeds. just check out the Nascar stockers. they reach speeds of around 200 mph with 357 cu.in. engine pusing a 3200 lb car. open wheel would be another interesting venue. even with the open wheels the cars really fly.
good luck at what ever body style you decide. try several.