I see. I should post pictures of mine, yours may be much better in that regard.
You have these larger "window" openings along the side to fish/blast stuff out which I don't. The other issue with mine, and possibly yours, is along the rubber rails (on the top surface) that debris doesn't roll to...
I hope you dont mind creative input on this rack. I never asked if you wanted it but...
I have something kind of similar, and when I get on muddy roads, like wet clay/gravel, my tires through mud a lot. I've collected a bit of mud and gunk on the roof, and sometimes it kind of rubs and...