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.

I have the same model and if I start the car and walk away with my phone, good luck getting Bluetooth to reconnect thereafter. Have to shut the car down for it to reconnect with the phone. Other than that, everything else is excellent UX wise even the navigation, however it's outdated so phone mount + Waze works great.

Hmm. I never started the car and walked away with my phone. Can't think of a situation where I need to do that. But then my phone is big and doesn't fit in my pocket.

I've also got a 2015 Mazda 3 GT and I absolutely love the system. It boots quickly and works really well. I got the CarPlay upgrade done though. Everyone that gets in thinks my car is brand new.

Is that a Mazda installed system? Do you know what version software you have? I know with mine, I had one of the last versions where a Mazda AIO Tweak install was easy. (Later they make it harder.) So maybe there were some improvements made to the official Mazda software in later versions.

Would also like to know if car play upgrade is possible, I'd love to buy the parts and do it myself.

I bought it in 2018.

the only problem with my 2019 Mazda cx-5 system is that the maps are stuck in 2008. It works, but you still have to go through many levels of menus to search and find destinations. Thankfully it supports carplay.