hi every 1 iam new here just trying to fit new cdplayer into my p reg gs 300 sport but i cant work out wots wot. there is three plugs on the back of the radio. i think 1 must go the oe cd chnger and not sure bout other two. it also has onboard amp not sure how thats going 2 work with the after market unit. the car has got 8 speakers far as i can see. so iam after a radio wiring diagrams which tells me wot does wot so i can figure few things. thanx u any help
thars