The hood prop rods are the best cause if a Big wind comes up it could slide your hood off the roof.
I like the quilt/blanket better then the towels as you have great protection/ better protection if the hood slides around any. I store the quilt/blanket in the trunk with the lawn chairs so it is no problem hauling it around.
Also if you take the wife for a ride you can always stop somewhere, get out the blanket, set it on the ground, get out your picnic basket, and make her day. (if she gets cold you have a blanket for her also.) Lol, Multiple uses.
David