Has anyone driven with the tailgate open and the hatch somewhat closed, I notice the hatch can't close completely due to the tailgate cables,

but if would be nice if there is a way to secure everything to carry some thing longer than 5 ft.

 

Yes, I put a giant cabinet in there and tied the top tailgate down using the windshield washer mount

 

I used an elastic bungee cord. Close the latch on the bottom of the upper door(part where it would latch to the lower door). Use the hook on one end of the cord on this and hook the other end to the middle seat latch hook in the floor. Nothing will be visible on the outside and you have no risk of scratching your door.