Carbon buld up on tail pipe
I've had my 1M just over a year now and I drive it mainly on nice, clear days. I have taken it on track several times and I drive it fairly hard but most of it is around town stuff.
The other day I looked at the tail pipe and there is a fair amount of carbon build up around the tips.
I don't wash the car much cause it never gets dirty, so I haven't scrubbed them ever. The car has just over 6,000 miles on it.
Does it need to be driven more? Harder? Or do I just need to scrub the pipes some?