I had a Navigator IV on my 2013 R 1200 GS and would like to purchase a Navigator V. Can I replace the Navigator IV with a Navigator V?

Yes. The holder of the navigation preparation on the K 1600 GT / GTL is fully compatible with the Navigator IV and Navigator V.
 

As the Navigator V has a bigger display than the Navigator IV, the instrument cover on the K 1600 GT / GTL motorcycles before 2014 must be replaced.
 

Only then does the entire screen of the Navigator V become visible. The matching cover for the navigation compartment can be obtained via your BMW Centre.