Hmm, I have used WD on the vert hinges before - never did anything bad. i have also used white lithium, but it is ugly.
on the brakes, on some cars (i cant remember is stangs are one), there are low-wear springs/indicators that are on the pads - they will rub the rotor and make noise when the pads need renewing.
if we dont have those, i would check rotor run out - sounds like one is lightly warped.
good luck.