ozboss, my device is nuvi 3790, and its maps are always located in a folder called "Map" either on the device or on the SD card.
So, I put the CN Europe there inside the "Map" folder on the SD and it's working fine. so, I should create a folder inside "Map" too and call it "JCV" and put the .jcv file in it. Right?
Because here I deduced that the \Garmin folder which you mentioned is equivalent to the \Map folder I have on my new Device.