I've had a problem witha trailer, and Green Flag stuck it on the back of a lorry and took it home whilst I drove.
Cost the standard mileage fee though, which gave me a shock.
tip - as well as carrying a spare wheel and hub, carry also spare wheel nuts.
Some Bas**** undid my wheelnuts on one side whilst at a service station.
10 mins down the road, wheel is almost off, pulled in, hub and wheel shot to pieces. could have put on both spare hub and wheel, but did not have the wheel nuts to do them up with again!