Eight o'clock on a Saturday.
The site manager opens the bay board: three bays, each a column of slots sized by the services booked, with a full valet on a large estate filling bay one until noon and the mobile van's diary down the side showing four addresses in order with journey times between them.
A customer pulls in without a booking; the manager adds the registration to the queue, the system prices a mini valet for a medium hatchback, and the queue screen in the waiting room shows him third in line with an estimated turn.
A subscriber arrives; the valeter scans the plate at bay two, sees an unlimited plan with two washes used this week and an interior protect included, and starts the job.