I don't know alot about physics, especially in racing, but my first thought looking at those picks would be with all that downforce, if you tuck in behind the leader, wouldn't that make it easier for the car to lift up off the ground? say you are travelling behind someone at 200+mph and he taps the brakes and you make contact... could all the downforce lift the car up and flip you??
just an uneducated thought...