nice DIY there brother. Specially for those who want to install systems in their 8th gen civics.
BTW a few things i noticed.
1. do something about the amp ventilation. if no air escapes amp will get v hot even on low loads.
2. For ground connection, there are 4 bolts in the center part of the seat, just under the rear arm rest, i think those points are better for grounding.
P.S dont worry about the cone touching the plastic ring of the door panel. i have 3/4 inch mdf spacer installed and they still dont touch each other.