As I had said before, I drive mine on weekends only, and that is sufficient to keep everything in proper order and get the harmful moisture out of the internals.
By the way, if you haven't received a letter from MB about going to synthetic oil on your A/B service intervals, beware! The "flexible service interval" computer (when the little crecent wrench ligght comes on) has not been coming on frequently enough, causing the unsuspecting MB owner to wait too long for oil changes (i.e. premature engine wear problems in the future)!
Mercedes-Benz is trying to solve this by going to synthetic oil, which can go longer between changes, in line with when your ML computer thinks it's time.
If you are currently using regular motor oil, disregard the computer, and change more frequently (I usually do it every 5K since it's not driven hard, and the trips are relatively long).
There is a long post about this issue...
2009 ML350 (84K) - Family vehicle
2001 CLK430 Cabriolet (71K) - Wife's car
2005 BMW 645CI (124K) - My daily driver
2012 Mustang V6 (60K) - Daughter's car