Taskos, is this brass metal ring "factory" or a "cure" you came up with?

I did not know there were different types of air cleaners used on these cars. I just ordered mine from Burton's based on photos of what mine looked like.
I still have the box the new lid came in but I'm at work so I don't know the brand name on the box.

I initially thought the problem was the inner piece with the plastic screen mesh was too tall putting pressure against the botom housing.

When I install the new lid, there is about 5mm of distance between the bottom half and the lid. I have to push down then twist the lid to align the arrows. That's why it keeps popping off.

With the old lid and the new piece transplanted to it, there is no distance between the housing and lid and I just twist the lid clockwise and it locks in place.

If anything the tabs on the older lid seem more worn out than the ones on the new lid.

It seems the problem is the new lid, not the element.

Once again, I have not driven my 2CV this week. I've got it cleaned up and have been driving my "dirty" Trabant this week to work. Since they have been calling for rain everyday.

Nut with M5 treaded rod works well for me.

Fixed the air cleaner lid today. Quite easy.

I used a 1/4 X 6" carriage bolt, a flat washer, Lock-Tite and a wing nut. I trimmed about 1/2 off the end of the carriage bolt once it was installed.

Tidy

Good job.

Sounds like the standard Burton (lack of) quality.
What was the reaction of Burton?

I never emailed Burton about the lid. I thought it was because there is part of the bottom of the air cleaner that seems to be missing. If you look at the photo, just below the carriage bolt (lid removed) you'll see what looks like a piece of plastic that is gone.

However I never had the lid pop off when I first got the car with just the foam element. Of course it wasn't doing much without the other piece.

I haven't driven the car since I "fixed" it but I can't understand why this wouldn't work. Unless the wing nut vibrates loose over time.

Just an update. The carriage bolt/wing nut fixed the problem. Normally intake noise sounds cool but for some reason on this car it was unusually loud and particularly irritating.

I guess because it sounded like a major exhaust leak. It sounded like one of the flanges coming off the driver's side cylinder head blew a gasket. Or is there a gasket there? Or just metal to metal?

Since aligning all the saddle clamps and getting the cross box hangers aligned with the bolts on the gearbox is a bugger. I've done this twice and it's something I'd rather not do again. I think I spent 3 to 4 hours on it.

I guess if you've done this a few times, it get's easier. Next time I'll remove the front wings.

Hint Front Wings

So much easier with the wings removed. And : -
"It sounded like one of the flanges coming off the driver's side cylinder head blew a gasket. Or is there a gasket there? "
Yes, there is a gasket between the exhaust port and intake port to the manifold. Or should be.