With all the soot on the bumper, I'm guessing yours has a bigger DP and decat, or sport cat?
The car won't smoke in 1st and 2nd. Not enough load on the engine. Shove the pedal down in 4th from 3500rpm and you'll likely get a ton of smoke
Stock lambda doesn't dip below 0.82 (12 AFR). I've seen aftermarket tunes dip well into the 0.7s, which explains the smoke. It's arse covering over fuelling. They all do it. It's a crude way of controlling cylinder temperatures.
Even standard you get a little puff of grey occasionally, but you should never have sooty bumpers. That really is excessive. OEM cats trap and burn off a lot of that excessive soot, hence my original question.