Update. Made contact with someone in Toronto who claims to have the software for rns510. He asked me for the delivery part # and the SW version #. I provided the numbers. He shared a pic of his radio, showing the screen with his numbers. Mine are slightly different. My Delivery part # is 3C0035684L. My SW version is 5374. His was slightly different. I questioned whether the software would work on my radio and was assured that the software would work. So, I intend to try it. Should have it near the end of next week. I will write an update once I have it installed. Thanks to those who chimed in on this. More later. One more thing. He also has the latest version of the maps. I decided not to buy the map updates since the car rarely leaves the island and the maps we have seem to work fine. Would appreciate opinions of the wisdom of that choice. He is mailing the disc to me Monday so I have time to change my mind.