I wrote to Garmin support regarding if it is possible to move G2S and DB files on SD card because my Nuvi 3760T main memory is almost full
They replied to me as follows:
Thank you for contacting Garmin Europe.
I am happy to help. The files which you mention would need to stay on
the device and would not work on a SD card. I would recommend removing
some different files from the device to clear up space on your device.
Please find below information on doing this.
1. Plug your unit into the computer
2. When the unit is connected, please click on ?start? icon at the
bottom left hand corner of your computer screen
3. Then you will need to click on My Computer or Computer
4. You should then see a file in here called Garmin Nuvi drive. Please
open this file
5. You will then be looking for a Voice, Text and Help
folder. Please can you remove all of the information from these folders
but make sure to keep hold of the languages that you need. Once done,
this should then clear a fair amount of space from your device.