Source is king. As they say in scientific research: garbage in = garbage out.
First thing to consider is whether you’re able to tell the difference between fidelity while driving in a car on a highway. We have the best audio system in any car but the highway noise, the listening space (the car) are less than ideal spaces to judge quality so I am not sure you’re able to tell the difference in the same track whether it is streamed in FLAC from a usb drive vs from Apple Music through CarPlay (wired or not).
For me, most of it comes down to how the music was mastered and recorded in the first place. Crappy recordings will sound as such regardless how you listen to them. Once you’ve established that your music is well recorded, then the USB>wired streaming>bluetooth streaming principle applies.
As to native Tidal, I have done a couple of A/B/X trials with my family and each time, I’ve found that wired streaming from Qobuz has sounded better than my native Tidal in the car. That does not apply to some of those same albums in ATMOS. For example: Tango In The Night (Fleetwood Mac). This album sounds AMAZING through Tidal ATMOS and is better than my wired Qobuz (non-ATMOS). I acknowledge that it isn’t exactly apples to apples but the listening pleasure is what counts.
Lastly, don’t be fooled by the ATMOS label. It is not easy to find those albums in the phone app and even harder in the native app. Some albums are truly gems but a lot carry that ATMOS label but are really nothing special sonically. I heard that music companies/artists get paid more for ATMOS files by Apple so they’re incentivized to deliver that format but don’t know that for sure. The amount of time and energy to create the ATMOS energy is often not worth it to the companies but the payments are.
Have fun.
