noise supressors are pointless tehy just aid the problem not fix it...it could be that youre RCAs are run too close to power/earth wires...the alternator creates an AC voltage that is rectified to 12V DC this AC voltage can 'jump' across to speaker/rcas if run too closely
more than likely its a bad earth tho remove all of them and clean em up properly
it wont be the remote tahts impossible as long as you have 12V going down it there is no problem because it puts no audio signal in so it couldnt possible create noise