Do you mean the rubber trim piece that goes over the lip?
(cue long line of posts from others saying "don't bother", "better without", "they cause the rust" etc.

)
But to answer the question... They weren't that expensive new from Honda, but annoyingly, the lude part number ones are no longer available
@Thebusofwoe is researching for me which newer Honda's have them at the same (or longer) length so I can get those as an alternative.
I haven't found a source through searches on eBay etc, unfortunately