Yeah, just drilled a little hole, but through the base, between the pleats, not through the mesh itself. The thinnest wire I could find was actually "doorbell wire." Cheap but effective. Bought a couple feet off a roll at the hardware store. Couldn't find "real" safety wire, the stuff you'd use to safety wire bolts and such. But it's a pretty low-stress application, and the loose filter thwapping against your leg, plus the crappy performance of an engine that's suddenly running very lean on one side, are your alerts that something bad has happened. Took me losing a couple filters before I figured that out.