Great discussion with very valid points. We all know the pitfalls of DPFs in urban environments, software updates etc from the VMs go some littleway to alleviate these problems as does correct cleaning procedure as performed on HGVs, ie oven cleaning and refit. It is not our job though to 'reinvent the wheel', let Government and VMs sort that one out. We should have what the Yanks have--a six year warranty on all emission related devices on the car-mandated by their Government. The same cars there, the same VMs-so why not.