you got an AAZ, and a big stereo dont you?
then you need a TDI/VR6 120a alternator..
boy, lemme tell you what! that 120a alternator is AMAZING..
my stereo has ALWAYS dimmed the lights in my car when you got it turned up..
even with 2 batteries hooked up, it would still dim the lights decent..
but then i did a serpentine swap, and added that 120a VR alternator (with ABA alt pulley) to it, and now, my lights DO NOT DIM, even when listening to quick dubstep with really tight bass, it still just pours the power to the batteries..
the difference between the 65a and 90a is big, but the difference from a 90a, to a 120a, is HUGE!!
the VR alternator was the best mod ive ever done to my charging system, hands down..
and i know you, like me, run a big stereo too, with more than one amp, and LOTS of current draw..
anyways, if you want a bullet-proof charging system, go with the VR/TDI 120a alt, a good batt under the hood, a wheel chair deep cycle in the trunk, and a capacitor if you feel the need..
i run no capacitor in my system now.. i always used get noise thru my amps with a cap installed.. now the deep cycle, being ~2 feet from my amps, has all the reserve power they could want..