I've owned my '18 for almost a year now and yesterday is the first time I'm hearing really loud whining/electric noises coming from it whether I'm driving or anytime I open a door or for a few minutes after turning the engine off. It never used to do this. I've read around and see some have reported issues with the amplifier. Again, mine is NOT the THX system; it's whatever Lincoln uses as the stock audio. Did mine bite the dust? What has gone wrong with mine?