Evidence of the duct can be seen on the car, when the car is not moving. Clearly the W03 rear wing endplate is quite thick, an access panel that houses the DRS actuator is outboard of the flap\endplate intersection, plus there is another panel in line with the beams wings intersection with the endplate. I’d suggest the duct is opened by the flap and hinge plate, the duct then routes through the double skinned endplate down into the beam wing. This then exits through the duct that mounts the beam wing to the gearbox. There’s a tortuous route for the duct through the car to reach the front wing, but this isn’t that dissimilar to the 2010 F-Duct routing. As with McLaren in 2010, the trick is to design the duct into the car at an early stage to minimise losses through the ductwork. This usefully makes it harder, but not impossible to copy. To copy this set up the monocoque needs to be altered and the nose cone needs the apertures into the front wing mounting pylons to feed the airflow into the front wing itself. This requires time to redesign and potentially re-crash test any changes.