This is a really crappy setup in this car - I worked with a group of car audio nuts for a couple of years and started with my own car at a car hifi competition in 2006 . No , my ears are fine - i started in a sound quality competition with a total of 740 W RMS @ 4 Ohms - not SPL (Sound Pressure Level) .
So i have seen a lot - windows blown out of cars , concrete filled car chassis , car doors bolted tight with 24mm screws 10 cm spaced around and much more .
Have you ever heard the entire roof of a 4000 sqm trade fair building rattle because someone forgot to close the door on a car . . . there's a lot of fun in this .
Let's see - there are 8 power amps SunDownAudio SCV-7500D rated at 1750W 4Ohms , 3500W 2Ohms and 7500W 1Ohm - if they are analog amps @ 4Ohms they will need about 300 A each for that or about 175 A if they are class D . For 7500W @ 1 Ohm class D they need about 750 A each . The power terminals take about 50 sqmm each pair - x3 = 150 sqmm - good enough . This might actually be real . . .
I can't see any fuses installed in this car - great work ! We use 500A fuses from electric forklifts for this kind of installation .
The amps are rated to work up to 15,5V so a 4-cell LiPo set might really be installed under the car .
Some SPL-nerds at the car hifi show here used 8 single cell solar batteries in series running the amps @ 16V !
Anyway - this car moves a lot of air - really loud is something else .