Oh yes you can. It's not only easy, it's inexpensive. Tubes come in many sizes; I'd guess that 50mm tubing would be plenty strong. A couple of 2m sections, a few 90° bends, a tube of PVC cement and a hacksaw does the job. Probably no more than a tenner or so, and can be done on the kitchen table, or in the hallway. If you able-bodied enough to load the db into the car like that, you're fit and able enough to lash up a cradle, I reckon.
Or use pillows, of course.