The good news is that if you own a Garmin GPS device, there’s a way to get free Garmin GPS maps. And in most cases, the free maps are much better than the expensive Garmin maps. I’m a big fan of Garmin GPS devices, but I always found it disappointing that they charged extra for slicelive.com: Cris Hazzard. How to Download Free Garmin Map Updates. The process of using the nuMaps Guarantee offer is very simple. On the Garmin site, in the Update Maps section make sure you choose the option labelled nuMaps Guarantee. You will then be prompted to enter the serial number of your Nuvi or Zumo GPS. We use open source maps downloaded to our Garmin GPS. A friend taught us how to download free maps to our GPS when we were in Mexico. We are forever indebted to him for showing us how to do this. It saved us lots of money since we didn’t have to purchase the maps from Garmin and the open source maps are updated more frequently. Detailed topographic maps and satellite imagery for your handheld GPS device. Get terrain contours, turn-by-turn directions and points of interest for hiking and hunting. Mar 24, · We bought a Garmin GPS about a year ago and I need to buy maps for Europe. Best Buy told me to buy a Europe card from Garmin, on-line, but I'm not sure exactly what I need. There is the City Navigator® Europe NT. Is that what I need? We will be in Italy, Switzerland, France and Germany.