He's referring to car window washers at traffic lights.
Maybe in Australia which has had them at various location in capital cities in the 80s, 90s, 10s by my recall. Maybe in other countries as while Troy is Australian he's moved about a bit ... but probably Sydney - it's one of those modern clean yet dirty cities with a bit of everything.
EDIT: The quote doesn't come from Troy, it's sourced from a twitter reply he received from "John" @j3g