They had M1 filters for $5-6??? Did you buy them all?Update, all,
I bought a Mobil 1 filter at WM today. The M1 was the same price as the Fram Tough Guard, and they have been out of the OEM filter, the AC Delco, for several weeks. This filter and the Dexos-rated Castol Magnatec should do me well for my short OCI.