Which year? My 2015 Mazda 3 Grand Touring has a kind of slow system. Boots slowly and a bit inconsistently. I've had lots of problems with Bluetooth (with three different phones, 2 Nexus and a Pixel), and often have to hold 3 buttons in to reboot the software. I've also had it black screen and reboot on its own. That being said, I used Mazda AIO Tweaks software to install Android Auto, and it's largely reliable. It does stutter when switching between music and navigation, and the music even stutters while turning if maps are on... but for the daily commute, it works fine.