in the very least get another battery and 0 ga wire and make sure to ground both batts with the 0 gauge.........nobody here is trying to steer your wrong man, only trying to help you from 1. frying your amp 2. starting an electrical fire in your car or 3. both.
and if you do start a fire, video tape it for us and kiss your car bye-bye because once the insurance man sees how the fire started....no monies for joo