Freebeard and anyone still here...
This is roughly what I'm trying to do (link)
https://1drv.ms/u/s!ApZC8QFk-svmgXNKbTVyLAgQpdaF
According to Flow Illustrator it
can work...what comes out of the wheel well follows the interior roof bottom line to the back and is released into the vacuum in the rear of the car. My question is if the inlet/outlet points for air in the interior or roof angle can be improved and how.