Alright, I'm sort of confused, and have spent hours/Days/weeks trying to figure this all out, but I'm sort of just in between ideas at the moment. I was told you guys were the best, and so I've come here! If you have any ideas, any help would greatly be appreciated. and I've tried to help out as much as I can in terms of information.. So essentially I'm at the stage where I already have; HU - AVIC-F910BT (http://www.pioneer.eu/eur/products/archive/AVIC-F910BT/page.html) Which for quick reference has Front, Rear and Sub pre-outs. 6x9's - JL C2-690TX (http://www.elite-electronics.com.au/In-Car_Entertainment/Speakers/Rear_Speakers/JL_Audio_C2-690TX_6x9_Speakers#.UgkNupIy1x9) and a 2 channel to run them for the mean time..Rated @70W RMS x 2... Conveniently. For now I'm planning to rewire the current speakers to a four channel amp (I was thinking http://www.elite-electronics.com.au/In-Car_Entertainment/Amplifiers/Multi-Channel/Boss_Audio_PH4.500_4-Channel_2000W_Amplifier#incar-speaker ?) Then setting the gains down to suit (it is a rather powerful Amplifier for the speakers). After that it's wiring up the amp I already have with the 6x9's, and hooking it all back up to the HU. With the aim to upgrade to Alpine Type R's (possibly four components) in the near future! And the sub (after that... As for my questions! RCA's - How do I get it done?! I was thinking a 1M-2F connector, hooking that up to the 4 CH via Front-out? Using rear-out for 6x9 amp and keeping the other spot free for the sub/amp? The reason for the rear doors is because I don't want the system to be too low-end heavy in the back (with a sub and 2x 6x9's). Good call? Essentially the amp would be running at 50% of it's capacity.. Is that too low? When the new one's are in I'll be setting gains on the point before they clip (I've been told they're severely underrated @ 110W RMS.. it would get the amp to near 70% of 'RMS' power) Would it be better to run two four channels, bridging one output for the sub, or three amps (Keeping in mind i have the 2 channel already.. or 2x 4CH listed above is powerful enough)? Are capacitors advised/essential / how do they work (Any "4-dummy's" explanation would be fantastic!) Speaker wiring.... I've been told 10/12AWG for subs, and 16AWG would be best-suit for the other speakers. Accurate? Using Seperate ground wiring for each amp.. is that how it should be done? Am I missing any crucial parts? (Bar obviously wiring, and power cable splitter) Anything else? (Advice? ) Thanks in advance for any and all help! Michael