Years ago I used to remove my ski rack from the top of my car when the temps reached the 50s and spring skiing had slowed to a halt, thinking it would save gas money and stop that occasional whistling emanating from the top of my car.
Then I wised up and left it on, using it as a summer rod rack. I know it seems risky, but I found that it works at up to speeds of 60 mph and is far superior to the windshield rod rack for long distances and potential clearance problems.
A few things to note if you try this:
One, make sure the rods are facing backward.
Two, make sure that if loading more than one rod you space them apart as much as possible as you don’t want the tips to be smacking into each other at speed.
Three, clean the rubber on the rod racks at least once before as it will help save your line from any built up road gunk.
Four, be cognizant of where your guides are before you slam the rod rack shut. Bent guides are no fun.
Five, make sure your rod is built and you have a fly tied on and in the hook keeper. Should one of the ferrules somehow come loose, the line will act as a safety line and prevent part of your rod from flying away.