After you do the big 3, You might want to run a 2nd battery to the trunk(optima). This with a little extra wiring can be a great setup. Most people go the wrong way with runnning dual batteries. This is more expensive but isolates all of your amp power away from the cars main electrical power,this is good as your head lights or anything for that matter will never dim or lose power unless your battery is fried up front.
If ya want to know how to do it just let me know
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