Quote from Gary Anderson:
“The exhaust acts like a compressor,” says Anderson. “It moves the air quite effectively, increasing the air speed, and that gives more downforce. The return will be small, but that’s always the case because the regs are so tight.”
Being a mere mortal I had not considered that this was the actual effect and the reason for blowing the rear wing.
How will this affect the wake of the car - surely it's a bad thing for following cars?