The COT wing probably contributes some to the flipping, but I think it's more the overall shape of the cars. In the mid-90s there was a rash of the slow liftoff kind of flips like Newman's this week. I remember Rusty, Ken Schrader, Davey Allison and several others having that kind of flip where as soon as the car turned around backwords all that downforce they have going frontwards reversed itself and lifted them off the ground. That's where the roof flaps came in and they really helped at first. There were several spins after that where you could see the rear end wanting to lift up and the roof flaps popped up and the car sat right back down on the ground.
Of course, these kind of wrecks were only at the high-speed tracks - Daytona, Talladega and some at Pocono.
Now there also are the kind of rollover wrecks that I don't think fall into the same category - like Lagano's this year, Michael McDowell's at Texas, even Mark Martin's on Sunday. They don't have as much to do with the aerodynamics as they do just getting hit at the wrong angle and it turns the car over. I don't think the COT, the wing, or even the general shape of the cars has much to do with that, it's more of just an accident like would happen on the highway.
