I find running the nav volume at the max number 7 I think seems to work perfect.
Even with the radio at a moderately loud setting I can still hear it just fine

 

Thanks, but I find the max volume too loud for day-to-day use, especially when the radio is low or not on. Wondering where others who feel the navigation system should automatically lower the radio have gotten with their dealers and/or corporate. Not something a software update shouldn't be able to fix, and not something we should put up with therefore. I plan to bring this up with my dealer and corporate early January...