As unexpected life experiences go, appearing in front of the Transport Select Committee is right up there - and finding myself discussing the stock levels of pig wee if we all run urea systems to cut NOx emissions quite something else again.

The invitation came about as a result of the combined readership of Autocar, What Car? and PistonHeads, which I represent as editorial director. The thrust was to distill the views of the consumer as best as possible in light of the VW scandals and subsequent fall out regarding whether economy and emissions tests are fit for purpose.

To discuss such diverse and sometimes contrary topics in just over an hour, with three panellists on my side and eight MPs - chaired by Louise Ellman - on the other, was always going to be a tall order. The upside was that it was a civil, well mannered affair conducted in a largely positive, non-confrontational and open-minded spirit.

But I was surprised by some of the lines of questioning, and the levels of expertise (or otherwise) they conveyed. The biggest conclusion I'd draw is a stronger conviction than ever that legislators and governments need to set aside preconceptions and let the experts do what they are expert at - but it was ever thus, and deciding who the experts are in the face of a barrage of conflicting opinion can't be easy.