More annoying than the day-to-day brake dust, is the 'brake muck' that comes out after a wash when the wheels are still wet.
I have a manual car wash a few blocks away. I save just enough time at the end of the wash to zip up and down the street, then jump back into the wash bay to hose the wheels off one more time. This gets rid of some of the muck that's thrown out. They still need a touch-up after, but it's a lot less to clean off.
You can see the MB heritage in the smart's brakes.