Help on rca wire interference

Hello, I'm Kris and this is my first post on here.  I've been doing some searching and came across some info that might relate to the problem..but, unsure what to do in this case...  It def relates to engine noise, and tried a few things in other post except a few...and wanted to get your opinions on this issue if any please...  I belive I've narrowed it down as much as i could, and would like your opinions if any please...

***first before i get into the details.. is this true***
"Ground loops. I will not even try hard to explain ground loops (they basically mean that there is a difference in how easy it is for electrons to loop back to the battery - for one of your components, fewer electrons can make the trip. The electrons look for a way to get home - back to the battery, that is - and they end up making the trip on some audio signal cables somewhere."

What i have...
A 2 channel Kenwood 7204 Amp (170 X 2 rms) with Rockford fosgate twisted RCA's running to my kenwood headunit DDX712 front RCA outputs
Also running a pioneer amp and subwoofer, and cannot hear any engine noise through the subwoofer when hooked up with RCA's

I have a power distribution block for the power, and a distribution block for the grounds to a shiney metal screw in the rear of my hatch. Scion Tc 2008.

I have a 4guage power wire running completely on its own on the passenger side.  The subwoofers rca's, the power cont. wire (remote wire i guess), and speaker wires for the components are running on the driver's side.

With the RCA's running from my Kenwood's DDX712 headunit's front RCA output to the amps RCA input i get all kinds of noise in my tweeters; from the turn signal, the rev of the engine when the gas is increased, the push and release of the break.  When I jiggly and wiggle the rca's running to the kenwood amp..it get's all wierd sounding in the tweeters.  I have this rca running completely on its own down the middle over the seats and def away from the main power wire.

With the RCA's disconnected completely the noises are completely gone, and just here a hissing sound in the tweeters (guessing that is normal to have a hint of hiss in the tweeters from the power of the amp) wired to the amp with 16 guage speaker wire (rockford fasgate wire).  

When I connect just the RCA's into the amp, and leave the headunit's RCA's disconnected i get a really bad noise from the RCA's cords themself.

Could this be the headunit being grounded through the stock radio harness?  I've been reading on the forum on what can really be the problem...but, every problem can be different on solving the problem