If you're in London then obviously a No No.
Outside / Skirts, 50/50.
Ulez clamping down again to the "inside M25 area" by 2021/2.
As Nick above said, people who want the big heavy german engines are still buying and don't really car about the costs of owning the car and are more interested in getting a good deal on the car than anything else. Sold a Jaguar Portfolio 30k on the clock on a 13 plate, no Ulez, he wasn't fussed but because it was a good price and had every possible extra fitted to it inc rear entertainment.