Swing Racers is currently in the approval queue at Apple and should be released soon, but in the mean time, you can listen to the soundtrack by Justin Mullins! I can't pick a favourite - they're all great and suit the whacky racing perfectly :)
Justin has been in the industry for a long time and has done audio for all of the Bioshock Games, Borderlands: The Pre-sequel, The Bureau: XCOM Declassified and more!