I’ve been trying to get OSM on my Nuvi 205w via SD card as well as USB mass storage. It doesn’t appear to be working. I’m downloading the latest img file from here: http://daveh.dev.openstreetmap.org/garmin/Lambertus/ I change the name to gmapsupp.img and put it in the garmin folder. The reason I know it’s not working is because my street is mapped incorrectly as going all the way through to a perpendicular street on OSM but it is mapped correctly on the Garmin map. When I install the img file, it is still mapped correctly.