First I will apologize if I've missed a thread on this already but looking for "How to's" on installing an AMP and SUB using the factory stereo in an 06 SE.
Does anyone know if the factory unit has RCA connections in back, or will I need splice them in?

 

You can't use factory amp for subs you need to buy an aftermarket amplifier to run the subwoofer. What you're using it does not have RCA connections. You will need to buy an aftermarket radio for headunit to have RCA connections for the subs but if you want to use your stock radio you can get a line output converter their pretty cheap at radio shack. But in my opinion you should just go with an aftermarket head-unit to make it easier and clean sound without "White noise" those can be heard if the connection are loose or using a RCA line converter which is very common happens with stock headunits.

If you really don't have the experience installing car audio system then I would suggest who knows how to do it and teach you how... don't listen or follow instruction on youtube or some websites... learn it from someone who can teach you in old fashion way.

How it really works with the amplifier

The Ampilifer gives you the power boost to the sound at extreme level depending how much (RMS) Rated power how much giving at certain amount at Ohms there is range of ohms 1-8 ohms from what I known. The lowest ohm you go the extreme more wattage is given.

Do not use preamp factory one came with the car that only does a job for stock speakers.

 

Thanks for the info, I appreciate it, I do have an aftermarket AMP - but yeah, I've never installed an AMP/WOOFER - I feel its pretty straight forward, but getting a head unit - seems to be the way to go, here. I prob shouldn't attempt it on my first go around..