Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:4816068.

This is an improvement from my previous rod holders (https://www.thingiverse.com/thing:4626401)
I wouldn't print these in PLA specially if you were going to leave them in your car for any length of time. I used 100% infill but I'm sure anything above 20 would work as well.

I usually have at least 3 rods on the floor in the back seat and they always managed to somehow get entangled with each other. This new version does a much better job of preventing it.