install won of these and be done with it, goes under seat
https://www.ebay.com.au/itm/Azur-AZ-803-8-450W-Compact-Active-3-Way-Car-Subwoofer-Bass-Mid-Amplified/173061746330?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649
https://www.ebay.com.au/itm/Azur-AZ-803-8-450W-Compact-Active-3-Way-Car-Subwoofer-Bass-Mid-Amplified/173061746330?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649