Thanks for the reply, I use the same MP3 player in our Jeep, I use a regular USB plug in (not micro USB) w/ a earphone jack going into the MP3 player and it works fine. The Jeep has it's USB inputs available on the stereo as "Aux inputs". I assumed the Taos also had those Micro USB ports available as inputs, but probably just for charging, which would really be upsetting as I thought these would be more modern vehicles w/ more up to date features. Hopefully I'm just missing something and there is a way to use the USBs as inputs, not just for charging outputs.
thanks for adding the extra detail, it helps understand what you're looking for.
Sounds like the Jeep had a non-standard usb implementation and included an electrical MUX switch that detected if you attached audio or USB. there should be no expectation that this is how all cars would work because this isn't a USB spec. its what Jeep did and it sounds like it was useful to a degree.
The USB ports (my SEL has USB C ports, not micro) in the VW are for charging, data connection for car mode on the phone and storage. This is the extent of what you get with USB connection or BlueTooth, except for the charging with BT connection. Plug in the phone and it will charge and show your contacts, who is calling/texting, access music on your phone, access phone apps on the car screen like navigation etc.
you can also plug in a tiny USB stick. I got one that is about 1/2" long so it wont get bumped much. 32-64GB is more storage than you'd ever need and we just leave it in the car. then it remembers where you left off when listening. (sometimes it does forget though, another bug). you could also just have the MP3s on your phone and listen to them.
Given all the options for playing mp3s on the entertainment system, it seems like the mp3 player wouldn't be helpful these days. it actually sounds like less functionality because you can't access the music via the safer to use dash screen instead of navigating the music on the mp3 device. that seems like a distraction. the external mp3 player would be very useful for a car that couldn't play mp3 directly and only had an audio input.