I confess (er, realized) that my FLAC and WAV file comparison is in no way scientific or studied, as my DAC peaks out at 192/24. So, I can't really make a valid comparison. A bit is a bit and both files should sound identical but when limited in scope that may not be the case. Call it an amateur observation.
For the record, I prefer the sound of the inverted phase button turned on when using my Yggy, so now you know which side I am on.
Our cars like WAV files. My wife and I both have Mazda's (2018 & 2020) and they are quite friendly for hi-res files, both FLAC and WAV and play 192/24. Varying ways to choose music. Reliable. Metadata comes from Gracenote, a database used by Mazda that I hope makes inroads and provides some consistency, or compliance, across the industry. I think Japanese-made cars do a great job of giving digital music owners some respect and American cars kind of ignore us. Some new Chevy's don't even have the ability to play USB files. I think, in those cases, you have to use the new USB-C port to dongle a player. Cheap ____.
But now, in my car, I cannot search by artist, etc. Due to wav having lousy metadata capacity, searching or filtering in my car is useless. The car's display does not even show me the name of the artist. It often shows "Various Artists", because that is the directory where many songs are, due to purchasing, for example, a One Hit Wonders compilation. When the songs were flac files, it showed me the artist.
That is because your songs are not indexed correctly. Syntax error. Many times compilation music does not include the artist name in the contributing artists field (but shows Various Artists instead), hence it does not index an artist.
In addition, the reason metadata is not downloading artist images to display is because if it has no idea of what photo to show of that Various Artists guy.
You need to fix data on your own database of music before you export it to your USB stick.
Don't overload your car stereo processor with too many tasks at once or include a large number of files to manage because you are likely pushing it. Probably better to use multiple USB sticks with differing music with say 10 GB on each. Mazda at 15 GB takes about a minute or so to load on start-up. It does have a memory in that it starts where it left off and if I turn the car off and back on it doesn't miss a beat.

