stereo wiring help please

[91RED3S]

i own a 91 turbo mr2 w/o factory cd player, and with rear spoiler, and i have tried several ways to wire my stereo, every where i go either didn't have the right harness, or insisted that i wasn't qualified to do it (bullshit if they had the right effin part i would just plug it in), so i tried to do it my self using schematics on the internet, most of which are wrong, and many of them show two plugs, if there are more than one plugs that have something to do with the stereo system can somone please tell me where to locate the smaller of the two and please tell me specific wire colors and what the go to, thanks for any help you offer