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let me explain... it wasn't skidding - I have mislead you. He was on a straight piece of road, and the back wheels all of began juddering and he knew something was wrong, he took foot off gas and the back end by this time was sliding, it hit edge of verge and then he rolled it down 10 foot bank into ditch. He didn't roll it as a result of speed - in fact he said it was bizzar ( sorry about spelling) as it all happened so slowly and he managed to get himself into foetus position before it rolled as he knew what was coming - it was just unfortunate that he was near the ditch, hence it rolling slowly backwards, not over and over in the road. He drives about 50,000 miles a year and relys on car for work and hence is a careful driver- he is not a young beginner and certainly no boy racer!!!!
Thanks for all your concern - he is fine and really counting his blessings. It did shake him up though!