No, we still have far more trees than tree huggers, so not a problem yet
I've seen the road police here stop trucks/really old busted cars that had black smoke out of the exhaust, so it is possible to get their attention as well =) But it must be really bad! And of course you won't get a ticket, you'll have to give them some money as always... On the plus side, there is no such thing as an emissions test.
As for Germany, judging by my colleagues from the German office, it is quite affordable to lease BMWs and Porsches, cause it seems every single employee has one
New car every three years is very easy to do if you're leasing!