I am about to buy a Suzuki Grand Vitara 2.0L petrol, manual transmission, 2006, hatchback. All seems fine with the vehicle including engine bodywork and internal condition. It has 127 thousand miles on the clock. My only concern is that the owner has told me that it makes an ocassional sort of dull or doh sound when he puts it into reverse. It works fine and the gears are all good. He has no idea what is the sound and is reluctant to spend hours and potentially money finding out. He has offered it to me for sale at a friends price of 1200 pounds. Any ideas please what on earth that occasional sound could be when reversing? I have looked everywhere on line but cant find anywhere to explain what it is. It has apparently done this for quite a few years but it has never affected the functioning of the vehicle. I woluld like to go ahead with the purchase very soon and I trust the current owner very much but am worried slightly about that sound occasionally heard when reversing. Can you help me please? Many many thanks.