Hi,
I think that the manufacturers change to the higher standard when they change vehicle production lines / introduce new models.
"Right On" folks who care a lot about the environment and emissions like VAG would,
oh,
yes, errr,
right,,,
Better check my documents as we LOVE being able to travel to London, even if we usually avoid the Congestion Charge Zone anyway (the ULEZ is based on this area I think.)
Robert