01 v8....Ok so I've been wanting to put in my subs but I've been procrastinating too much. I had to jump my buddies car the other day and realize I forgot my battery is in the f'ing trunk!! (I know I'm a genius ) lol...so correct me if I'm wrong all I need to do is run the power wire about 2 ft down to the battery and run the rca's up to the factory head unit. I've never ran subs off a factory unit but I believe I have to buy some kind of adapter? I also wanna put my 4 channel on the interior but I'm afraid I can't do that myself with the factory amps already there and what not. I got the alpine 6 disc system any advice is appreciated.

rewire the 4 channel amp to all speakers. it would be a lot better if you bought all new speakers and just ran the cables from the amp to each speaker and then connect the rca cables to the head unit (will sound a whole lot better, but if you want ok sound stick with the stock ones, theyre ok...) you will connect a separate battery to your stock one next to the spare tire and use your new battery to connect all the amps to it. youre going to run 2 power cables, one to each amp and then ground both amps. then connect the rca cables accordingly. to be honest most amps come with instructions and just follow. just dont connect all the amps to your main battery (personal preference: i have 2 15" kickers with a separate battery and a capacitor, the capacitors may not be necessary but i just want my battery to die on me some day. i've had this set up for almost a year and no problem...) connect the subs to 1 main mono block amp, and to the battery and then the rca from the head unit to 4 channel amp and from the 4 channel amp to the subs amp... this works for me... hope its some help...

thanks....I've never done a 2nd battery though. How would I connect the new battery to the original one?

you dont need 2 batteries just do what you said in the first post and use the rca module i did this in mine and mine soounds great had to turn bass down because everything rattles to much for me i like a clean sound

You dont need an adapter but it will probably take about 2 hours to wire the RCAs in the stock headunit. I also agree you wont need another battery.
Wheres the stock 4-channel amp BTW?

to be safe so u dont burn your car up take it to an audio shop and get prices on them doing it for you. better safe than sorry. goodluck