I have a T30 Highline SWB 150DSG Panel Van which has been prefessionally converted to a full blown camper. In addition I carry 3 bikes (about 40Kg) on a rear door mounted rack and tow a boat trailer with around 30Kg of down force. With this set up a large proportion of the weight is over/behind the back wheels which is leading to a low back end ("saggy arse syndrome" as Walski puts it) and very poor traction when pulling away and I think the van, with all my gear, would become pretty much useless with the slightest bit of snow or ice. Would uprating the rear suspension help with this problem and provide more traction on the front? If so what do I need to look at so as not to affect any warranties and/or insurance. (For info; I asked similar in another thread in the Camper Van forum earlier but feel it sits better here and will, hopefully get me more response).