Even for a car running at a constant ground speed around an oval, the wind will not offset. If the car is driven at 30 mph (ground speed), the car's airspeed will drop from 30 mph to 0 mph when a 30 mph tailwind is added, and increase from 30 mph to 60 mph when a 30 mph headwind is addeed. Because drag is a function of airspeed squared, the detriment of going from 30 to 60 is greater then the benefit of going from 30 to 0.

Hoarse: loved your comment about not knowing the wind is at your back until you turn into it. Been there, done that.