A great post as others have said,

Just one note though, Pete Mutlow wrote:

>>> All of this in the name of "Global Warming." When you consider that only 2.5% of CO2 emitted into the atmosphere is man-made and a tiny proportion of that figure is produced by the motor vehicle,<<<

Its nothing to do with Global warming, in fact a vehicle fitted with a working DPF will produce more CO2 than the same vehicle without one.

This is because of the conversion of PM (which is predominately Carbon) into CO2. Its all about air quality and what we breathe in.

Mark