I have a 1997 dodge caravan. i am wondering what i should add to my van and how much it would cost to do so. What i would like to add is a head unit that can play cds and connect to an ipod. i also am wondering how much it would cost to put a couple of subs in. i am wondering if it would be worth doing so based on the cost. also, if i want to add subs, do i need to buy an amp as well? any help is appreciated