In the film Back to Back starring Apollonia. She is in the back of a car whilst travelling and in the car stereo Appollonia's song 'Since I fell for you' can be heard playing. I wonder if that was her idea!
In Beverley Hills Cop when Eddie Murphy is at a club you can hear Vanity 6 'Nasty Girl'. Shame it wasn't on the soundtrack.
I heard Sheila E's 'Droppin Like Flies' in an episode of Beverley Hills 90210.
I am sure u orgers can think of some more. See Ya!!!