Hi Peter,
I've obtained another just in case, and it doesn't rattle. Nor did the unit removed, but if the loose component will be OK, I'd rather leave it on. I weighed up the risks on the day. It is a bit more awkward for me to get back under the car to effect a swap than the average person, and I have a gut feel that the filter is better made than to be "broken" by a drop of a metre to the floor. I wondered if anyone had experienced the phenomenon and found it to be non-critical, saving me the bother. Agree with all rationale expressed!! Had there been the slightest in