I have a Volvo s80 mki with 160A alternator.
2x 100Ah AGM batteries and a 500F Maxwell capacitor in the trunk.
Focus Fx3000d @ 1Ohm and 59V. (3000-3500W @ 1ohm, stable in some setups @ 0,33Ohm)
Soundqubed HDX 315d2 in a 104l tuned to 29Hz, plays flat to 24Hz.
SPL Dynamics ice150.4 class-AB amp for mids and highs. (150Wx4 @4Ohm, 190Wx4 @ 2Ohm)
SPL Dynamics MD200.4 class-D amp for midbass and rear deck. (200Wx4 @ 4Ohm, 300Wx4 @ 2Ohm)
2xBass Face PAW10.1.4 as midbass in glass fiber pods in front doors. (May be ported in the future if possible)
(I heard someone i know tested them with 400W