Thanks. Not worth the $400-$500 for roof racks. I am not an aeronautical engineer, so I cannot calculate the lift involved. It will not shove it off the roof, I am confident of that, but have the safety straps anyway. The advantages are many. When parked in the shade, I can make it portable and place it in the sun. I do not have to store a portable panel. It can be moved from vehicle to vehicle. It can be removed for those months when it is not needed. It is always, "on and working" when driving.