[JayTee2019]

Wondering of installing a proper placement of roof mounted vortex generators might help?
They wouldn't be too visible upon the roof and might kill or reduce the wind noise.

Look for them online. Available in different sizes and from quite a few vendors.

 

[nicholas.lee]

In some way I found a solution. In Hawaii most people buy rail wraps that are padded and Velcro around the rail, so when you put a surfboard on, it doesn't damage the board. I finally put mine on the back at first and still had the noise then front and the noise went away. I didn't test further by pulling the back one and then knowing if it's the front, back or both rails causing the noise.

 

[JayTee2019]

In some way I found a solution. In Hawaii most people buy rail wraps that are padded and Velcro around the rail, so when you put a surfboard on, it doesn't damage the board. I finally put mine on the back at first and still had the noise then front and the noise went away. I didn't test further by pulling the back one and then knowing if it's the front, back or both rails causing the noise.

I've seen some put sliced swim tubes or some ot those water pipe insulation foam over cross bars as well. and then wrap in a few places with tape.