I recently converted some MP3 files to WMA. These files will play in one vehicle from my USB, but another vehicle will only play one-third of them. I know it's not the converter because some will play and others won't. All the other songs on my USB are also WMA and they play correctly.
Car stereos are finicky on what they will do/won't do.
Play some and not others suggest organization/file structure car stereo doesn't like. How many files are we talking about? do u put them in folders? how many folders. Some car stereo are finicky over long folder/file names.
In the future I suggest load everything on your smartphone and BT it over to the car, works all the time, every time.
I put them all in folders exactly the same on two different USBs. It used to play them on both USBs, now after I switched them to WMA, it won't play some. Also, my car doesn't have Bluetooth. It might be 50 files.