My wife's 2013 Edge Limited ecoboost is having the exact same problem! When you intially start the vehicle the musty/moldy smell is most prevelant, then, the smell will occur randomly as you are driving the vehicle. Another issue we are expierencing is momentary heating while the A/C is on, all of the sudden the A/C will start blowing warm air without the system being under load. By not under load I mean not excellerating or going up a hill. At this point really regreting trading in the Audi Q7.
Has anyone seen a service bulletin on this?