I don't recall seeing anyone wear them either, not that I've paid that much attention to their attire, other than to notice teams seem to be wearing matching colours for the past few seasons.
It didn't occur to me that their might be a rule against wearing them, just that as they're not the greatest choice of racewear, people would have more sense than to pick them.
If it is against the rules to wear them, American tradition or not, don't wear them. That rule should be simple enough even for Jordan to understand.
They aren't in America for the bulk of the Race anyway.