Wasnt there someone who made a set of..wings or spoilers or something that was attached at the back of the sling to help with this exact problem? Whatever happened to that? Do they work? Maybe that idea needs to be revisited!
SSREAPER
@roadog1aj came up with thed esign for rear side air deflectors cut from a plastic 5-gallon hbucket. See here - Roadog's D-Mod - Post # 16. He used 1.5" spacers as standoffs, but it's an easy change to use larger standoffs that might hopefully provide more airflow.
I plan on playing around with this mod once I finish my remodel and get back into mod-mode. I'll likely use diamond plate to match the rear panels I make and try to find a configuration that actually provides enough airflow across the wheel to make a difference (notice I didn't say eliminate the problem). At the very least it can look cool and provide some more color and interest back there.