Some considerations since I've tried several variations: Rods should be pretty secure, at least at one end, so they don't bounce around. I've tried bungie elastic and straps, but the bouncing and vibrations will wear on your rods wherever it is sitting, be it on the handle or the blank. Another consideration is that you should have a window that opens in your shell and also in the back of the truck if you use the longer rods (>7')
Here's what I came up with and it works great...
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No permanent modifications were made to the shell or truck. For the rear attachment points, I used the existing bolts for the rear shell window. For the front supports, I used the appropriate sized dowels to fit the head restraint attachments. I never used the rear restraints since they restrict my vision. Any areas that contact the rod are covered with the soft part of a piece of velcro.
Hope this might help.