MAZDA 3 MULTIMEDIA NO FURTHER A MYSTERY

If there was A much bigger OEM Mazda selection then I'd Choose that, but as far as I am aware, there isn't. So I'm trying to find advice, from people who have transformed their headunits or that have an improved understanding than I do (not very hard) of what the results might be. I am happy to be proprietor of the head-device, every little thing