Out of curiosity, I got to looking at some stuff on O'Reilly's website earlier, and thought I'd check to see what their oil filter selection looked like for my BMW 535d. Turns out their house brand MicroGuard is a re-packaged Mahle OX404, and it's $5.79. I ordered it online and will pick up tomorrow to make sure everything's on the up and up. If so, I'm buying several more.