connections

I have a 2006 Honda Odyssey with a 130amp factory alternator. I have done big 3 with ground to chassis and engine ground. I run a 2000watt RMS mono block at one ohm to an 18" ampere audio subwoofer (2000watts RMS). The sub is wired with 4 gauge wire with banana clips and 4 to 8 reducers for sub...