I cannot answer your question directly, but you could probably find a horsepower calculator online and see how many Watts you'll need given the approximated drag coefficient, your speed, and the frontal area of the car. You can them downselect a motor that meets the power requirement. This is probably a crappy answer.

Touring car, 2S 4.5T, ~70mph with proper gearing and boost. Ran on 3 cell that'd get you close probably. Drag is your enemy at that speed.