PW - I've done it twice. Both times I loaded front first, all the way forward. Didn't even feel anything behind me as I brought the cars home.
First time was Tulsa to OKC when I had a water pump fail me.
Second time was this - bringing my spec car project home from Jon (78F350), He's in Eastern Oklahoma, I'm in Southwest Oklahoma. Truck drove fine, Boxster and trailer towed fine.
Rick
Edit: looking through some pictures, I remember another time a few years ago when I U-Hauled home another fine example of a mid-engine, 2 seat Porsche.
This one was sitting in a barn in the Texas panhandle.