Someone asked me to (I'm really sorry I can't remember who it was) make something to cover their lapbelt boss. theirs was full of grot and just asking for trouble.
So I designed something to cover it.
the first version was fine but the hole was full of grot so when I screwed it in it jammed and snapped off (ok, I shouldn't have been using a pipe-wrench...)
So the bung needs to tap the thread into the grot and clean it out and it needed to not be ugly, maybe a nice carbon fibre weave appearance.
also, it doesn't need to be billet aluminium or cost the earth
so here we are:
£13 delivered.
https://uberniche.co.uk/lapbelt-bung