I am moving at the end of this month, planning to add the yakima roof rack system to move my full size mattress. After some research here, I am going to purchase the Yakima Q towers (set of 4) 4 Q clip set 2 58" cross bars and the heavy duty strap all from Amazon. Am I missing anything?

 

that sounds about right........unless you want to add a fairing which greatly reduces wind noise.