I am currently using SGS3 and just updated to Android version 4.3. I drive a lot due my work and Spotify has been my best friend during these trips. One of the biggest thing was when I bought my Volvo S60 that includes integrated bluetooth with A2DP support - no more playing with wires.
Last thing what I am missing is song information from Spotify to car audio display. SGS3 itself can deliver data to the car (example when playing mp3 on Android's own music player) so the platform supports the feature but when using Spotify only "Streaming" is diplayed on screen. My wife's Nokia Lumia 720 (Windows Phone 8) with Spotify can do the job, my cousin's iPhone 5 with Spotify can do the job but my SGS3 cannot.
I understand that Spotify is offficially not supporting bluetooth but since other platforms can send song information via bluetooth (apparently also some Nexus'), is this only a platform, brand or software issue?