It seems like they butcher the clips on that panel more often if they're using 1/4" material -- the fit isn't perfect and they try to mash it up in there.
As an aside, the clips might've been brittle, anyway. 16 years of NC heat eats plastic. Tonight I shattered a never-used connector tucked back in the wiring harness on my car's interior for the same reason.
best, whit