Experts; polishes (5)
I believe the answer is:
buffs
I believe this clue is a double definition.
'experts' is the first definition.
(I've seen this before)
'polishes' is the second definition.
(buffing is a kind of polishing)
(Other definitions for buffs that I've seen before include "Experts" , "Aficionados" , "Enthusiasts" .)