Moving project

My son and I are in the middle of building his RV7. We're in the middle of the left wing, fuel tank is on, outboard leading edge is on along with both top skins and the inboard bottom skin. We need to move the project a good 120 miles. I told him that we can strap in a cradle and tie the cradle down in a Uhaul. He's afraid the wing would bounce around in the cradle and damage the leading edge. He's also afraid the straps would/could damage the trailing edge. He's sort of thinking lay it down On a mattress/thick cushion and strap it down. Does anyone have a good suggestion on the best way to transport it?