The secret to Red Bull speed
Observing the car in Spanish GP paddock Red Bull's exhaust design might just be responsible for as much as half of their pace gap on the rest of the field.
The typical exhaust arrangement concludes at the top of the tail bodywork, but the RB6 has a much lower positioning, at the side of the gearbox and lower wing-post mount.
This causes the hot exhaust gases to dump into the double-diffuser, producing incremental downforce from higher air volume and resulting pressure. It also appears to clean up airflow at the rear of the car; namely the rear wheels.
This difference could be visibly noticed watching the rainy Chinese GP, noticing the spray diverting around the rear wheels, and avoiding the resulting turbulent air from the rotating wheel.