That explains why I had to grind my rear pads to get them to fit!According to Brad on thunderbird.com (06-05-2010), "Ford no longer recommends using the "rattle clips" on the rear calipers and the new pads are slightly longer than the original to accommodate the clips being gone. ...... Ford doesn't sell the clips anymore either with the new pads or separate. .... I (Brad) ended up buying a ceramic set at Autozone that came with the clips but the pads were the new bigger ones and they didn't fit if you used the clips."
My recent experience (April 2014) is the same as Brad's -- too bad no one in Ford parts told me that the newer pads were longer. and the clips were not needed.