Reviewer: Jennifer Davlin from United StatesModel:GM5163

-All of the documentation says the maximum memory capacity is 16GB. Well, 32GB works just fine! Even their “Live Support” said 16GB max. 

-NAV: 

-The maps that comes with the unit works well. 

Trivial Cons:
-An EQ would be great. It has separate treble and base, but a 5 band EQ would be much better. 
On the Mazda’s left display, the display item that shows the radio preset or the artist/album/title just displays “audio off”. 
-I had to modify the harness that came with the GM5163. I cut the audio wires and put male RCA plugs on them. Then plugged them into the GM5163’s low-level audio out. This really isn’t a con since they said I’d need to modify it for a Bose system. It did work without the modification, but the lowest volume setting (1) was too loud.
-A2DP doesn’t sound quite as good as the OEM radio (but it is close!) 
-MP3 volume could be a little louder, but this may be just the way the Bose amp is. 
Probably has nothing to do with the GM5163. 

-The steering wheel phone control don’t work which I knew before buying the unit.
I’ve read that there is an adapter that connects to the CAN bus that detects the phone buttons. Ive also read that it is impossible because those buttons interface to the Mazda Bluetooth module directly. At any rate, if I figure out a way to detect the button(s), the GM5163 has two wires on the back that may be able detect them.