Despite my earlier post, I do have some regard for the source (and provenance) of manufacture, and would generally choose a product made in Germany over a product made in Mexico.
As a former inspection engineer (sadly now retired), I had experience of inspecting samples of a very large batch of Mexican engineering tube, which my customer had doubts about.
They were of very poor quality ... So poor, in fact, that the whole batch of some 13,000 tubes were rejected.
I then had the job of testing 100 per cent of the replacement order, which was made in the UK.
They were found to be satisfactory, with only a small percentage of rejects.
BUT
Buying a "German" manufactured product can sometimes be surprising.
Many parts in MBs are manufactured in countries other than Germany ... Some in other EU countries ... Some from elsewhere.
I recently bought a Siemens washing machine - Partly because of the "German" tag, but also because of previous satisfaction with German domestic appliances.
What do I find on the manufacturer's plate on the back ?
You guessed it ........ Made in Spain.
Having said - as above - I've never had problems with Mann filters of any type.