Just to add on the DPF removal and soot...
I'm a US based 335D owner and I had my DPF removed and ECU tuned this past fall. With normal driving, I see no smoke at all. Although, there is definitely a more rich exhaust smell when at idle, or first pulling out of the garage. I only see a cloud of black smoke in the rear view mirror when I floor the pedal hard. There's also a bit more sound to the exhaust, but it's more of an increased resonance...and by no means obnoxious.