Dealer is gouging you on the price - no way it is $600. Search the forum threads on nav...many are less than thrilled w/the lack of real-time traffic updates.
Personally I'd save $575 and get a phone mount and use Waze.
Depends on model year... $500-$600 is not unusual for pre-2016's. A hardware module has to be installed.
Personally I'd save $575 and get a phone mount and use Waze.