That was interesting.
Are you sure that your Scanguage is working correctly ?
Imagine if that airflow coming in through the window could be channeled out the back of the car and used to reduce the wake
This would involve removing the hatch glass ( or the entire hatch ) , reclining the passenger seat and folding the rear seats down to make a smooth pathway for the wind.
It would not be pratical ( rain, wind noise, strange looks, family abandonment, loss of girlfriend / wife etc ... ) But it would be an interesting test though wouldn't it ?
And easy too !