MTP Support for Android audio via USB

[Metal Wing]

Not quite sure if I am posting in the right place and if I will get any kind of response that I don't expect, but...

Made the switch from iPhone to Android (no regrets, hate them both, really). But one thing that annoys me about Android is that starting with JellyBean firmware, there is no more Mass USB Storage mode... Meaning I am not able to play music over USB in my car anymore...

I would very much like to use my Android phone and play music in my car (2013 Mazda 3 GS-SKY) via USB. Because Android now only supports MTP, and not USB mass storage... I am not really sure what I can do :/ (As a side note here, I prefer not to root my phone, despite the fact that it takes like 3 clicks)

But my question is... what about an aftermarket audio system? Anyone knows one that would support playback from Android via MTP? Or perhaps there was a firmware upgrade to Mazda computer, so the next time I go in for servicing, they can update it, and it'll support MTP? Or any other solutions or options I can try? Most of my researched shows that unless Mazda supports MTP, I am SOL.

[sp3GT]

Just a thought, can you enable USB debugging on your phone? I don't think you need to be rooted to do that?

[Metal Wing]

Just a thought, can you enable USB debugging on your phone? I don't think you need to be rooted to do that?

That was the first thing I tried, yup. Sadly, it still didn't play audio via USB, no matter how many times I hit the button on my dash to switch the audio source.
And as far as rooting goes, even if I do, most solutions are "works on specific phones, with certain kernel only", so even that doesn't seem to be 100%...

I don't necessarily see MTP as a drawback of Android (since supposedly it is a better protocol), but I do think it wasn't wise of them to get rid of USB Mass Storage device mode either...
On the other hand, I do read stories where auto maker updates the car's firmware to support MTP. So that brings me hope.
And if I need a $300 aftermarket system... well, something I can plan for myself as a birthday gift or something, in a year... or two :(