I have a 2 year old Autotrail on a Ducato and last week went for 2 new front tyres, the fitter had to knock the wheels of with a sledge hammer. I would have had no chance of changing the wheel at the roadside. The fitter greased the hub before refitting as this is a common problem. The wheels were obviously not removed when serviced a few weeks ago by a reputable garage. Something I will make sure they check in the future.