Stereo & Electronics - should i use car stereo front rca?

Or run another rca cable from the front to the rear?

And if i do run another rca cable which side should i use to run the wire under the carpet when i already have the power cable on one side and a pair of rca cable on the other? So i don't get noise from the rcas.

Forgot to add i will be using a 2 ohm amp with 4ohm 6.5 speaker componets.

Yes - run another pair of RCAs to maintain individual control over speakers. Run the RCAs down the same side as the other RCAs you already ran. Power wires on the other side.

Thanks!