and the hopper radio is playing "fly away" by lenny kravitz and the 90s pessima is playing "candle in the wind" by elton john.
That's the one I've noticed so far. Only because I crashed in such a way as to put the radio display in the normal field of view. However I believe the Darude - Sandstorm one was discovered quite a while ago.
There is/was a thread that listed all easter eggs in the game & the different songs playing in the cars, one of which was Sandstorm