in sd/Map you can rename your .img as you like, for example CNEU.img
It works fine in two diffrent SD cards, one for US and the other for Europe.
I donīt remember if the names before this update was, gmapprom or gmapsupp but now it seems like both maps have same namn.
I have nuvi40.Downloaded CN EU 2016.20 on SD card,only unlocked map! Later I found "aditional files" in the same folder where the map was.Some of them are not supported by my device.So,only "split screeen JVC" I transvered to the SD card in folder named JVC! Now everything is ok,have line assistant,junction view and so on. All the best!
New Version is here: [Only registered and activated users can see links. ].