The other advantage of FLAC besides being lossless and occupying about half the file size, is that it handles metadata robust and consistent manner that works in most playback systems. WAV is also lossless but doesn't have consistent metadata and doesn't compress the file size.
Does it matter to have lossless and even High Res audio in a car? Our brain is very good at filling in the missing information of a lossy compressed file like MP3 and AAC which is why it can seem like a fairly subtle difference in sound quality. The problem is that your brain is working hard and you get tired - audiophiles call it 'listener fatigue'. It is more relaxing and engaging to listen to the higher quality recordings.
There is a new format coming - called MQA - that is about the same files size as a FLAC 16/44 CD file, but it 'unfolds' up to 24/192 and includes other features like removal of time smearing caused by digital filters used in the recording process. I don't think any car systems have it yet, but high end audio products are available with the decoder. All the major music labels have signed on and all the streaming services are lined up to support it. Thankfully, it is backward compatible so it can play on any system at 16/44 CD quality. Tidal is already offering it as 'Masters' available with a Hi-Fi level subscription.