I'm installing a new CD radio in my 1987 328, according to the diagram with the radio each speaker should have a solid color wire and the second the same color with a stripe, usual in my experience. In the 328 wiring diagram I have it shows the striped and solid colors as being different ? It also only shows 3 speakers ar rather it shows three on the diagram but there are two woofers with the same number. Anyone figured this out in the past? I am not keen on pulling of the door covers to check the leads on the speakers.