^ sounds like a grounding issue with the oem head unit. Usually the wire is connected to a flimsy little bolt. When I had my aftermarket single din head unit put in, my local car audio shop said they had to go in further in the console cavity to find a better piece of metal to bolt the grounding wire to
2009 2.5s with Takeda sri, Stillen front strut brace, 6k HIDs, black matrix depo tails, glossy black roof vinyl, LED drls.
future mods: lowering springs, Racingline or Stillen rear sway bar, 4 channel amp, catback exhaust, better rims