I want to add AU/NZ maps to my Nuvi 2545 LM but it is not listed as a compatible device under that map - will this be a problem?
In support my device is not even recognised.
That'll just be an error in the list. The map will still work. However the 2545 is quite old now, you may find it better to buy a new device with those maps already installed, as maps bought separately aren't updateable etc