Roland Perry gurgled happily, sounding much like they
were saying:

Of course, first you have to realise they are a vicar, or that the
vehicle is an ambulance on call.

As with vicars - except more so - ambulances on call tend to have some
rather unsubtle clues visually identifying them.

Not that the vicar's vocation was a particularly relevant factor in why
the police shouldn't have kicked the **** out of him...