Where to put music on Android phone?
 

If I want to play music from my Android phone, where to I put the files so that when my phone is connected to the car via Bluetooth, they will play?

Put them on a USB stick, not your phone.

Will I be able to navigate the folders on the USB stick, through the built in Lexus infotainment interface?

Better audio quality?

I made a folder called music and put all my music in there in other subfolders by artist and albums. I then use an app from the Play Store called Folder Player that I like a lot.
You can copy over from your PC with a cable or wirelessly using another app called Send Anywhere.