Sparky- I remember hearing half a dozen years ago that atmospheric pollution due to transportation amounted to 10% of total pollution. But there is a finer point; the individuals (motorists in this case) are easy prey and are far from having organisations and lobbies like major polluters (industry). And who'd go into the trouble in inspecting and enforcing regulations on house-holds (which are, IIRC, more significant polluters)...
So, the easiest way is to exact heavy toll from motorists. For a government, 'tis a bit like stealing a candy from an infant.
Funny that you mention it. Today Pa Wolf went to registration renewal for our Fiat 126p. The exhaust analyser claimed the car had incorrect emission. The reason: factory data claims 2รท3% CO, whereas (due to his points and carburettor adjustmens) our car had 0.9%.
