Years ago the Skoda garage in the next town tried to charge me £10 “for insurance” on a courtesy car when my vehicle went in for a service.
I refused on principle as it was “part of the lease deal” and insisted over the phone that they collected and returned my car to my home address, which they duly did.
They had the car for approximately six hours, and the result cost them much more (two drivers and a vehicle) than the £10 they would have made out of the “courtesy’ option.