If the closest garage is 20 miles away from the dealer, how does that dealer fill up all their new cars or traded in ones, that arrive with not enough fuel to get 20 miles away? Every dealer i had a car on the scheme from, there is a garage within 1 or 2 mins drive.
I return the cars with the fuel light on and it still can say 25/30 mile when it comes on. It saying 10 miles should be enough, unless you know the garage is further away, why would you leave 60 miles in it, for the next buyer and for people to do test drives in.
Plus it’s part and parcel of their job, that they getting paid for doing. Personally i wouldn’t leave it on fumes neither would i leave 60 miles in it.