I used these exact racks on a hire car for a surf trip down south. I found that because they rest directly on the roof, (as opposed to the sil where all the strength is) that the roof sank in a little. The roof bounced straight back after but I made a mental note to not use them on my car. The front of the sup that was strapped on wobbled and bounced up and down pretty much the entire drive from Canberra to the South Coast as they lack rigidity of proper racks. The straps which run inside the car and under the roof tended to soak up the rain and wick it into the car and then drip... and depending on the shape of your roof the strap gets in the way of your head as you drive or your passengers. I'm no giant either.
Other than that ... they were fine.

In short I'd use them on a hire car but not on my own.

Sharper said..
I used these exact racks on a hire car for a surf trip down south. I found that because they rest directly on the roof, (as opposed to the sil where all the strength is) that the roof sank in a little. The roof bounced straight back after but I made a mental note to not use them on my car. The front of the sup that was strapped on wobbled and bounced up and down pretty much the entire drive from Canberra to the South Coast as they lack rigidity of proper racks. The straps which run inside the car and under the roof tended to soak up the rain and wick it into the car and then drip... and depending on the shape of your roof the strap gets in the way of your head as you drive or your passengers. I'm no giant either.
Other than that ... they were fine.

In short I'd use them on a hire car but not on my own.

Sharper's right . I've used a similar product called soft racks . Long trips and rain are bad cause of the internal straps and drips . Also if you travel with your sup in a board bag , it will slap like crazy onto the car roof (noisy and annoying) . The only good thing with the board slap is you cant here your missus whinging if it is raining .