This is phenomenal. Racing games, for me, are all vibes anyway, and this nails it.
IF you're looking for others' thoughts, IF you're planning different songs for different tracks, then I think it would be so cool to be able to shift that organically rather than from a menu, so it wouldn't feel like you're picking songs from a tracklist, but driving to different places in a connected world.
As is, this is already one of my favorite GBC racers. :)