I have an 08 vehicle which is a great drive except for a constant rattle/thump from under the rear of the vehicle when driven on suburban roads. The local Ford dealers agree there is a noise but, after changing the shock absorbers twice, are now scratching their heads. I have checked for anything loose & tried removing such things as the spare wheel but with no luck

. The vehicle has only done 10000 mls & has had the noise since new. Can anybody help?