Most UK BMW owners tend to debadge 520d's... they think people can't tell that it's a '4 pot' diesel, but it's pretty easy when it's got a single exhaust.
I can imagine a lot of 120d owners doing the same as it has the same exhaust as the 123d.
I did consider it for my 135i because it makes it quite stealthy, but given how much money I am spending on it and how vain I am
I want ppl to know that it's a 135 haha!