Luckily in my previous life I worked in automotive for 25 years. Corporate level with GM and Mazda in engineering.
When I first picked up my van in June (after waiting 6 months), the TPMS light came on. I contacted the dealer and was told that my van was the second one with the issue and that an engineer was coming out to try a fix (did not work).
When I met with the engineer, we spoke the same language, so I was able to understand their dilemma and was patient with the repair try.
After he attempted the fix, I explained the other "issues" and he told me he would report it when he returned.
I have been in constant contact with him and another engineer to try and address the other concerns.
As for the radio, I asked the same question about using rear speakers. He mentioned that the conversion market is installing rear speakers by just attaching wiring to the bulkhead connector at the back of the radio. He said it works, but I have yet to try it myself.
He also mentioned firmware upgrades that are coming to deal with other issues with connectivity with Bluetooth and other functions. Could me months away!
Other more pressing issues like the TPMS and break noise and some engine issues.
That is what we get for a vehicle with modules built in Italy, shipped to Mexico for assembly and then shipped to the US and CA.
In the 90's when I was working for Mazda USA we had the same translation issues with the Japanese. They had trouble understanding why an American would complain about something a Japanese driver would not.