Having a problem with my 2002 Focus SE Wagon:

I've tried, without success, to remove the lid of the air cleaner assembly
to replace the filter. What has happened is that two of the four threaded
"nuts" affixed to the bottom half of the assembly have broken free and now
turn with the bolts holding down the cover. To make matters worse, these
nuts are smooth-sided, so I can't get a wrench on them. I'm able to hold the
front nut with a pair of Vice-Grips, but the rear nut is inaccessible.

I took the car to a Ford dealership (it's still under the bumper-to-bumper
warranty), but the dealer has accused me of breaking the assembly and
refuses to do a warranty repair. I called Ford customer service, but they
have basically said they side with the dealer in situations like this and
that I'll have to work it out at that level (not likely to happen).

I'm curious if anyone else has had this problem, because it really seems
like a design flaw in the air cleaner box assembly.

Thanks,
Carl