I am trying to help upgrade the stereo in his boat and figured you guys could help with some of my questions. The Boat is a 88 and it still has the original tape deck and head unit. The unit is oddly shaped and the newer DIN units won't fit. My friend has decided to stick with the unit because he can still use a tape adaptor to use his IPOD. The "system" has two 6" speakers and that is it. First, he wants to add another pair of speakers in the rear. Can I just splice into the existing speakers and run wire to the new speakers? Secondly, he wants to add a powered sub, like Bass Link. I know how to wire the power, but what is the easiest way to incoporate it into the current setup????

Jason