I had the Model 3 with premium audio for 2 years (VIN 144xx), just took delivery of Model Y (VIN 31xx). Here's my quick observation, based on about an hour using the same playlist (some Strauss, Bach, Holst, GusGus, Donald Fagen, Röyksopp, SHAED, Lindstrøm, Pink Floyd, Pat Metheny, The Orb, etc.), source is iPhone 11 Pro from Apple Music (with high quality streaming 256kbps AAC) over BT.
The two sound very similar, but the max sound level on Model 3 is higher (smaller car volume with same amplifiers and speakers, I presume). Also, low bass is noticeably stronger on Model 3 compared to Model Y, but overall they are very similar and pretty great for OEM stereo. Took the rear license plate holder off right away, but still had some more rattles on the Y. Unlike the video above, I felt the Y was not quite as good overall as the 3.