4x10 pvc tubes at home depot. The end caps are snug enough to just slip on without glueing. I have a roof rack, but you can use foam blocks and strap them to your roof. Works great and is cheap!!
Open the back window. Put one end of the shipping carton down where a passenger's feet would go...the other end rides sticking out the window...works for me...
I've moved rolls in rather small cars. A Honda Fit and a Nissan Versa. By putting the end of the roll up on the dash, against the windshileld, there was just enough room to close the back door/hatch.