The Citroeon 2008 C5 VTR 2.0 ltr diesel is the best Citroen I have owned and I have had Citroens since 1982. This car has conventional steel sprung suspension which is of a multi link type at the back end. Unfortunateley it has developed an annoying knock or rattle from the near side rear corner when travelling over uneven ground such as shallow potholes or dropped street grids. I have checked for wheel bearing wear, broken springs, loose links and split rubber bushes but all seems to be in order. The knock or rattlle sounds like something loose in the boot but it is not this as I have emptied the boot and done a test run. It occurs after the rear wheel falls into a shallow pothole or dropped grid and the suspension produces its normal 'thump' followed by the knock or rattle that I am refering to. I dont think it is anything serious and is not apparant on motorway journeys, but it is annoying and the only minor fault that I can find with this quality car. Rocking the car up and down whilst stationary produces no knock or rattle. Any ideas on what could be the problem?