Paul,
thanks for raising this issue.
This could have a devastating effect on the traditional kitcar industry. The way I read it anyone building a car that needs an IVA will probably have to fit a new'ish engine fitted with a CAT to meet the current MOT emissions standard.(Or spends hundreds of pounds trying to get an old engine to meet the current MOT regs if at all possible)
I think the requirements and implementation time-frame are both completely unreasonable!! (The feedback timescales are also unreasonable).
Whilst we should all be looking after the environment, the impact on the world of a very few kitcars is infinitesimal.
Time to do battle....
P.S. I have written to Adam Wilkins (Complete Kitcar) and Steve Hole (Totalkitcar) to see if they can drum up some industry support to lobby.