The clearer air is a good one. As I see it it went something like this:
UK accepts freedom of movement.
Approx 2m people come here
They bring their cars too, obviously
Some of them are German cars
With cheat code for the emissions tests.
We fail our pollution targets in many big cities.
We get stung with fines for being too polluted.
... all for upholding their precious freedom of movement rules, and for cars that we didn't make in the first place. Well thanks a bunch EU.
Of course they don't negotiate any compensation for people who bought these cars, as they've done in the US. Nothing more than
a slap on the wrist from the EU on our behalf.
https://www.politico.eu/article/european-commission-strikes-dieselgate-deal-with-volkswagen/
It's hardly surprising that they weren't interested in dishing out any punitive fines if you remember how they stood up for
us during the beef crisis:
https://www.theguardian.com/uk/2002/oct/03/bse.france
The problem is there is no overriding principle of fairness in the EU. They shove some money here, some money there, and we're all supposed to think they're wonderful as a result. It's other people's money. EU tax payers money. Our money.
So what?