There would be a difference between an indoor track and an outdoor race. Indoors, I can see the draft making a difference at 12 meters. I doubt it would help as much outside.
Apples and oranges, but if you're driving a car at Indy, then the draft is as important as if you're racing a bike. In that situation, if you can see a car in front of you, then the draft is affecting you. Straights at Indy are about 3/4 of a mile long. So you're talking about an effect that acts over a hell of long distance in this case.