As mentioned by others, consider yanking the front wheel, then hiding as much of the bike in the wake.
A receiver hitch-mounted cargo box,the shape of a truncated aerodynamic boat-tail would be the ultimate ( bike loaded in diagonally ).It would secure the bike, provide additional storage volume,plus knock down the drag coefficient.
AeroStealth ran the Brett Herndon AeroLid and Herndon boat- tail, reducing his 2014 F-150 from Cd 0.408, down to Cd 0.31. Cybertruck territory!
