I would assume a cover would help. The pollen, unless agitated while on the cover, would likely not simply "fall" through it. You'll likely get some penetration, but it won't be as bad as without a cover.
So long as you've got a nice, clean, smooth finish from waxing/polishing/clay bar, I don't think there's any one thing more you can do to assist with the pollen issue... it'll "stick" regardless... how adhesive it is will depend on your exterior finish/detail work.
If your surface is CLEAN (no wet/damp dirt, road grime, etc.) get a dust brush (made of microfiber, etc.).
So long as you've got a nice, clean, smooth finish from waxing/polishing/clay bar, I don't think there's any one thing more you can do to assist with the pollen issue... it'll "stick" regardless... how adhesive it is will depend on your exterior finish/detail work.
If your surface is CLEAN (no wet/damp dirt, road grime, etc.) get a dust brush (made of microfiber, etc.).