I just wondered if all MCS produce black sooty deposits on the back hatch. After each washing my mcs has black deposits on the hatch after only 10-15 miles. The dealer claims this is normal. I suspect that the engine is running very rich.

 

Your dealer is correct. It is normal, and all MCS (and Coopers too, I believe) run quite rich. That's also a good part of the reason why your fuel economy isn't quite as high as "estimated"

 

I don't get any black soot on my boot, but my chrome tips collect the soot pretty quickly.

 

Yeah met too. I see this black soot collecting only on the chrome exhaust tips only.

 

I get road dirt on the boot fairly quickly but, it doesn't appear to be exhaust soot.
The tips on my "Flow" get sooty fast.

 

same here, only carbon deposit on the chrome tips only.
None on the bumper. your car's running too rich. Id get a
15% pully.