I have to admit I haven't googled this subject much yet. Researching so many other things right now.

But for a 1500W car stereo, should I bother to upgrade my stock electrical system? Or just make sure the alternator & battery are in good shape?

If I do need to upgrade or add in-line capacitors or something, what is the norm for the 3rd gen when it comes to options?
I'm pretty good with car stereo, but this will be the highest wattage system I've had in a loooong time.

 

Okay, I've googled some more and found out about the "big three upgrade".
Also discovered the GMC alternator upgrade for our 4runner.

Now I'm having trouble finding info on how to best run a 0 awg from the battery into the back of my cargo area. That cable size won't fit under the carpet.

 

you can run the o gauge up and under the console, then under the back seats up to your amps. or you can run it under the truck, and up through the floor to where your amps will be. if you go under the truck, be sure to secure it to something solid, secure it often, and use grommets when going into the body of the truck, so you dont risk bare metal rubbing into the wire and causing a short.

 

There you go nice searchin

And when I ran o gauge just as said above under the truck is your best bet it's too thick to stuff anywhere. Also start looking into a yellow top battery with an isolator.