1990 stereo with MP3 inputs?

[droptail]

I want to wire into my OE stereo an MP3 input.

There is an unused connector with these pins available that I think will work, labeled:

11L-AUX LF-1
12AUD-C LF+2
13R-AUX RF-3
14AUD-C RF+4
15VOICE GRN5
16GRN P-LT6

Does anyone know what inputs I would use?

Thanks