I've been using 5.5" pads with the 5" backing plate. I received the XMT bottles in a PC starter kit, so I've been trying to put them to good use. I used XMT on a Toyota Matrix, Hyundai Elantra, Corvette and 2 Mazda 3's with less than desirable results. Just this morning I used M105/M205 with 21#...