I'm in the same boat, my neighbor parks his car 10' from the window in my herb room, so I can't even box it in and use it as an intake because it would look suspicious to see someone's window with a hole that's making a humming sound as a duct fan pulls air in....
The problem is flowering, smell isn't a problem during veg, but holy shit when you flower the entire level of the house will reek.
Gotta make an air tight flower area and filter the air in a demilitarized zone before letting it go back into the house.