When negotiating my used Limited this is what I was told about updating to Nav:
Sorry for the delayed response, I am at Ford of China these 2 weeks. Hope all is well.
To answer your question, you can add Navigation to the My Ford Touch system, if you have the customer purchase the A3 Navigation Card and update to new Performance Upgrade. You will have to have your dealer, reflash the SYNC software with Performance Upgrade and load the provisioning packs/maps, etc. Your service people should know how to do this.
If you have any other questions feel free to contact me.
Thanks,
James
Ford Motor Company
SYNC Technology
Just waiting for the parts. Will update once I find out more. Hopefully I was not lied to :/