It may be that all other subscribers to this newsgroup may be well aware of the following information but I certainly wasn't.
It recently became needful to remove all the wheels from my alloy wheeled VW vehicle. Vehicle was jacked, axle stands inserted and all fasteners removed. This was the point at which progress ceased! I could not budge any of the wheels. The solution was to "thrash" the wheels on their external faces with a rubber mallet in order to break the corrosive bond between the hub locating boss and the wheel. Corrosion occupies more space than metal and in this case all clearance had been taken up by this means. It took considerable force of hammer blows to release the bond and I was very glad I was not trying to achieve a wheel change with a puncture, in pouring rain/ snow. It would not have been possible to remove any of the wheels using purely muscular effort!
All the wheels have now been cleaned up on the locations and a light smear of lubricant applied against further problems of this nature.
The vehicle was five years old and it was the first time the wheels had been removed.
Hope this may save someone from the same discovery in an emergency situation.
Regards