My 2001 Winnebago Chieftain 35U lost a rear wheel cover after a careless tire mechanic failed to tighten the bolt covers.
I recommend checking this lug covers after tire work.
Does anyone know a source for used Winnebago parts near Sonoma County?
I find looking long enough to find a used one to match is not worth the time on this level of expense, so I would look at new online. Requires finding what cover by looking carefully at pictures to match and then doing a search for price on that specific item. Note that they don't come with the nuts to hold them on, so check if those are needed to be added.