i have two hobies, an outback and a revolution. i used to car top them on a chrysler t & c using thule load bars. i carried them upside down,strapped to the roof with both front and back bumper lines. i would get a lot of wind noise from the straps across the top. i think the noise was caused by the doubled up straps vibrating against each other. i started runnig the loose end of the straps in between the doubled straps to seperate them and this seemed to cut down on the noise. sounds like twisting the straps would do the same thing. i now have a malone down easter that i trailer them on and use malone gull wings , i think it is , to cradle the revo. the outback goes rail down on the load bar that is encased in a pool noodle. i prefer the gull wings to the thule cradles, i think it gives it better support.

anyhow, as long as you carry your yak on the roof, you are going to get some wind noise. thru trial and error you should be able to eliminate a lot of the strap noise.

now if someone can tell me how to eliminate the roof noise caused by a recumbant trike, i would apprecaite it.