[Cycle]

Well, for the exhaust, it'll be via a Coanda Effect nozzle. That will mix the engine compartment air with the engine exhaust while providing more air than the engine exhaust alone can provide, while also helping to pump cooling air through the engine compartment when the bike isn't rolling, so things don't overheat.

The heat from the engine compartment, along with the engine exhaust heat, will expand the air, helping to fill the wake.

The radiators will be in the cross-over ducts, used to mitigate side-wind effects. They'll exhaust near the widest part of the body (lowest pressure area) in vertical slits that put the air out parallel to the aft part of the body. Thus, a warm (less dense, thus lower friction) laminar boundary layer to reduce skin friction, that hopefully stays attached all the way to the tail.

The tail will be a narrow Kamm to reduce bike length and side-wind effects, with the engine exhaust-driven Coanda nozzle in it to pump the engine compartment air and engine exhaust into the wake.

One thing I wonder about... you see on some cars those small corner ducts at the front to grab the air and direct it where the car designers want it to go... would putting something like that (with a gap that's only as wide as the boundary layer) at the back of the bike, and directing that air around the corner of the Kamm tail before smoothly exhausting it into the wake have a beneficial effect?

I'm thinking something along the lines of a shroud that grabs the boundary layer air and puts it through a shape that's the same shape as the Coanda nozzle, but a bit larger... thus you get a "Coanda nozzle within a Coanda nozzle" effect to pump that boundary layer around the corner of the Kamm tail and into a small wake.