I transported my watertender 9.4 boat like this on top of my van. The wind noise was ear deafening. Because the wind was flowing around the seats of the inside of the boat. I had to turn the boat over and transport it right side up.
Good job! Good to see the bow line, although I would triangulate it for more resistance to wind. Also, if you put your strap buckles on the driver's side you can check them with your hand out the window and at a glance when you pitstop.
did you buy any boat ? I am planning to get West Marine WaterTender 9.4 Rowing Dinghy.I have not place for trailer too and I do not want trailer broke on the road thats why I wanna carry on my roof.