I have a 2017 Mazda6....bought an SD card from Wish.com for $30 and it's working well but it's not in color. From what I've read, any SD card you buy is not updateable unless you use the "toolbox", which works intermittently. My question is, can I buy a Garmin navigation system and mount it on the dash and just not use the factory display? From what I've read the Garmin maps system can be updated as needed and costs a whole lost less than an SD card from the dealership ($400) or GPSupdates.com (who do offer the latest map update for $130) ? Thoughts?