My apologies.
I had switched to a video showing the caps, and mistakenly thought that's what the discussion was about.
I like these caps. Are they made from smoked polycarbonate?
Could coroplast be used the same way?
I'm still wondering why they made the holes so big, maybe to fit a wide variety of wheels, but it seems to me they could be much smaller and have less wind resistance. No zipties or any other type of attachment is needed, as long as the caps keep their strength over time.