Hi, I just picked up a Nuvi 55LM. I did a map and software update with no problems. It updated to CN North America NT 2021.20 Lower 49 States. My other Garmin Nuvi's have CN North America All 2020.20. I'd like to replace the CN North America Lower 49 States with the CN North America All version. How do I do this? Also if I add a traffic receiver cable will it do traffic? Thanks, Jim