Has nothing to do with the tweeters, I think. Even with the sound all the way to the rear and the treble all the way down there is a terrible high frequency. It's so bad I get tinnitus (ringing in the ears) even at normal listening volumes. If I ignore it I get a headache. Went to the dealership, they replaced my tweeters, apparently they were blown. Thought that would fix the problem. It didn't. If anything the hands free link is even worse with the ringing feedback noise because it has fresh tweeters up front. Now I know why they were blown. They are so over-driven with high pitched sound. I spoke to the top guy at the dealership and we listened to another CT. Same thing. I should have leased, not bought. Should have just gone with Ford. I can't afford to put some fancy new stereo in this thing. If I did it would probably wouldn't be compatible with the Navi.
The stereo is worse than junk, it's unusable, possibly even hazardous. I think I may look into some sort of consumer protection org. See if this stereo actually poses a health hazard to the ears at normal volumes. Unfortunately the lemon law probably doesn't apply to car audio systems. I would love to get a full refund.
I bought the car to replace my pickup truck because it has a back seat. My wife is due on Christmas and I wanted something I could safely carry the kid in. I couldn't imagine playing music for my kid and subjecting him/her (it's going to be a surprise) to this torture. Although I probably wouldn't because I don't (can't) even listen to the stereo anymore. I can't take the headaches and tinnitus, not to mention how angry I get when this happens. This has COMPLETELY ruined the experience of buying my first new (and first foreign) car.