You must be fucking mad. Let them order a taxi.
I base this comment on one single ‘experience’. A friend ran a couple of courtesy cars for his various scumbag customers (car sales + a workshop) & then one day one was wrecked. A proper job, driver pissed-up, a number of parked cars smashed up, the courtesy car looked like it had been dropped out of an aeroplane.
I don’t know how insurance companies work but as well as the NCB, the policy was loaded & his next year’s bill (which I saw) more than doubled to over £8K and that was after he’d pared back cover. Over the next few years it must of cost him a five figure sum, all for someone who walked away financially scott free.