You'll here more options with this thread than Carter has "Little Liver Pills". Our coach has the Ford Sync System with Navigation but I still added the Garmin RV-770 as a back up because it has such specific RV programmable data and guides you around low bridges, list campgrounds and fuel stops, etc. Good luck with your research.
2018 THOR Chateau 35SF
Two Labs, Bugsie & Blondie