Is it possible to add additional maps to Garmin Nuvi 30

First time poster, so please be gentle with me!

I have a UK region Garmin Nuvi 30. I would like to use this in the USA, to save having to pay a fortune for a rental sat nav from the car hire company. Is it possible to load a US map (Florida specifically) to the Garmin? I have tried downloading a Florida map and adding it to the Garmin in the same directory as the existing .img files but when I start up the Garmin I still only get the option for UK.

Don’t put the new map in the same folder as the existing .img files; place it in the folder “Map” instead (create it if it doesn’t exist)

Thanks for your reply, that worked perfectly.