g'day, have hooked up an ipod to my amp with a switch which alternated between head deck and ipod using rca's so I can use both through speakers without changing plugs. this works perfect, BUT, I also have a in-car holder and charger in one for the ipod. As soon as I hook this charger up to the cigarette lighter and the engine is running I get that engine feed back crap which is usually associated with a bad earth. Amp has a decent earth, but the problem gets strange as the cig lighter seems to be earthing through the ipod-rca's-amp. I know this as I have taken the earth off the pwr to cig lighter and it all still works. any suggestions? using a boss 2 channel (budget but does job) amp. must get rid of this feedback noise and able to use ipod holder and charger. please help