Not sure how many people knew about this, but I sure didn't. We get 3 years of free map updates with our Mazda3s. If this is in the manual or Nav book somewhere, woops. I prefer flying by the seat of my pants. 
https://mazda-na.naviextras.com/shop/portal
Go to that website, click "Free Map Updates" and then download the PC Client. You'll need the SD Card out of your car (in your arm rest) and an SD card reader on your computer. Your computer might prompt you to "fix" the SD Card, click NO.
There was already 1 map update for me. I considered waiting to register and extend my 3-years of free maps a little longer once some big improvements were made, but it looks like your subscription is actually linked to the date of vehicle purchase. Clock is ticking! Registering also enabled my 60-day trial of the connected extras (traffic, gas prices, etc). Not sure how that actually gets activated in the vehicle - maybe through the SD Card. Wondering if this also kicks in my SiriusXM trial.

https://mazda-na.naviextras.com/shop/portal
Go to that website, click "Free Map Updates" and then download the PC Client. You'll need the SD Card out of your car (in your arm rest) and an SD card reader on your computer. Your computer might prompt you to "fix" the SD Card, click NO.
There was already 1 map update for me. I considered waiting to register and extend my 3-years of free maps a little longer once some big improvements were made, but it looks like your subscription is actually linked to the date of vehicle purchase. Clock is ticking! Registering also enabled my 60-day trial of the connected extras (traffic, gas prices, etc). Not sure how that actually gets activated in the vehicle - maybe through the SD Card. Wondering if this also kicks in my SiriusXM trial.