I have an 04 Corolla with an rp2000 on 1 zvx12v2 sub. I bought a pretty big dual 12 box tuned to 32hz. The port wraps around the back and is as long as it can before it chokes itself, i had 2 sdrs in it at 1400w but on the lows I could tell they weren't doing what they could have. I bought a zvx and covered one of the holes on the box with 3/4 particle board, liquid nails, and screws. The box was originally designed for 2 vxf subs but this zvx made this box sing down to 23hz. at 27hz my trunk is moving around 3/4 inch with the bass. From 29-40hz it gets deep in my ear and I can see birds flying off of large fields in a circle pattern to my car driving past thats a good 150ft of radius. I also forgot to mention around a month after i started running the zvx I moved the box around and was able to invert the sub and keep functionality of the back seats, it got a good bit louder around 32hz and 22-25hz, a good bit more wind from inverting it. I want to build a box that fills my trunk to the point I only have a few inches to my back seats when they are up (i dont crank when the seats are up one of my seats are already not latching properly and seems to be broken on the inside, having the seats down make it a lot louder) and use an aero port instead of a slot, i understand I can adjust an aero port to fit my liking after I initially build the box. I want to use 2 zvx12s on a taramps 8k since they arent much more expensive than just another rp2k for a second one. I dont know what electrical I would need for an 8k, i have a 900cca agm battery with a big 3 and 2 runs of 4awg to the amp. I think I would need an upgraded alternator because the stock one is 80amps and isnt exactly happy with my 2k. Would I be able to just run a 2nd battery in my spare tire compartment? Im going to move my amps to the spare tire compartment to fit a bigger box. I'm pretty sure 3 runs of 0 awg would be good or 2 2/0 awg runs. I would like to retain my back seats but i am willing to cut a hole in my rear deck for an aero port to stick through. I want to buy an aero port that is sectioned so i can start really low and shorten it until im happy. I got a really big crack on my windshield that hasnt gotten any bigger for a while. It grew 2 feet across my windshield in a day as it flexed but then just stopped, i want this box to finish it off. My corolla has a 1zzfe, has there ever been a dual alternator mount for this engine? Including wires I have around $1200 into my car and I want to put another $2000 into it over the next year or 2. For mids im going to do dual 6.5 pods in each door with a super tweeter and delete the 6x9s. I have a taramps ds440x4 but will likely upgrade to the skar rp150.4 for more power. Any suggestions on where to start or what I need to focus on are greatly appreciated. I dont know if this is what i should do or if I have completely gone the wrong direction and will sink my money into a shit system. I will also be doing a dual 18 build in my convertible starting with rockville dj 18" subs after I get my corolla where I want it. All critiques are welcome I'm a little in over my head on this idea but I know with time it can come to reality.