Wow overly impressed with our stock pads!
I went ahead and swaped out all four corners with new pads. I went with the ceramic all around...
http://www.oreillyauto.com/site/c/de...3351&ppt=C0068

http://www.oreillyauto.com/site/c/de...3351&ppt=C0068

I have about 86k on my stock pads. The fronts had about 1/4 inch left on the outside pad and about a 1/3-1/4 on the inside. The REARS were another story. First with the one at question the rear inside pad wore groves into the rotor on the passenger side..so that had to be the noise. Overall I had about 1/4-1/8 left on all other rear pads. I drove it up and down the street about a mile or so and everything seems to be fine. So it looks like it was the inside passenger brake pad scrapping the rotor. I swear I heard no indication until it was too late as all other pads were not in this condition, in fact the fronts looks fine.