Wheel fell off

Took delivery of a 2009 Forest River Lexington on 29th March.   Spent our first three nights as rookie motor homers at the club site at Longleat.   Fantastic site and staff.   Spotlessly clean and could not be faulted.

Heading north on the following Monday and a few miles on the M5 Motorway I noticed a slight vibration.   Was travelling at 50mph with the cruise control engaged.   Thought at first that it may have been a variation on the road surface.   Said to my partner that I was going to pull over to check for a possible puncture.   Signalled, slowed down and pulled onto the hard shoulder.   Just as I was coming to a halt I looked in the rear view mirror and saw the rear NS wheel fall off.   Luckily no one hurt.   Called the RAC who turned up after about one hour.  Patrol man realising that he could not handle this size of problem contacted his base to request a large recovery truck.   Recovery truck eventually arrived and was much to small for the job.   Eventually about 1930 hrs large low loader arrived with mechanic.   He tried to jack up the motor home and it was then when the inner rear wheel fell off that  I was able to see the remaining studs.   It would seem that all the wheel nuts had unwound and were probably somewhere on the M5.   RAC man recovered three.   Two with clean threads and one with a broken stud in it.   I can only assume that when the unit was given a PDI the wheel nuts were not properly tightened.   The outer rear wheels are 16 inch 8 stud alloys.   Does any member know of any company  in the UK that can supply 8 stud 16 inch wheels, alloy or steel?   Not impressed by the service from the RAC.   Each call took between 10 and 15 minutes to answer and they did not keep in touch.   Was stranded on the hard shoulder of a dangerous M5 for 6 hours.