My experiences using the USB flash reader for music.

Recently I took my car (2019 Prius Prime Premium) into my local dealership for an oil change and detail and someone stole the flash drive I had in the car. Of course the dealership claimed that all of their employees are little lambs and that couldn't happen.
So I bought a new SanDisk Ultra Fit 128GB USB3.1 Flash Drive which cost me $16 on Amazon. I loaded it with 80GB of music which didn't take too long using a USB3.0 port. Mostly mp3's but also a lot of FLAC files and one folder of WMA lossless. It took quite a while to index all of these during which the browse button is grayed out but it still plays the file it was playing. Once everything was up and running I found I could browse by folder pretty easily. The odd thing is when it plays FLAC files (made using Exact Audio Copy) it reads mp3. When I played the one folder of WMA lossless it correctly identified it as WMA.
I hope it doesn't have to re-index every time but I'll soon find out. It works but it doesn't show album art. The sound quality is good but is of course limited by the rather poor woofers in the doors. I've thought of having a car audio place replace the door speakers with Infinity speakers but the idea of having them rip apart the doors scares me.
This is really a poor design compared to the Pioneer head unit I had in a previous car but the touch screen navigation is very nice.

 

Update; It does indeed need to re-index every time but just to look for new files. It takes under a minute to be up and running again. If you were already playing a song that will start playing right away. Now if you added a bunch of new music then it will take longer. It works. Not like we are accustomed to having things work instantly but good enough.