Not surprising, if you wiped the car with a damp white cloth after parking over one damp night the filth on the cloth would be an eye opener, goodness knows just how much filth we breath in, i doubt most of it is pollen.

I changed mine recently and was also surprised at the condition-it looked at though something had eaten into it!

Perhaps it has. I serviced my Audi's air filters a few weeks ago and one of them looked as though a mouse had tried to make a nest from it.

I think they should be checked every 6 months, especially in dusty areas

Only in Arabia. Prompted by the need for an air-con re-gas (first time ever - well done Ford) I have just serviced our 17yr old 131,000m Focus pollen filter for the first time. Only one third of it was seriously bunged up with dry black dust and debris, the rest of the pleats were just black and dusty. I held the pleats apart to clean with a stiff tooth brush, then squirted water through each pleat from the inside surface. Should be OK for another 13yrs ;-). Anyway, microfilters are unnecessary - do we have pollen filters over our window frames? All that is needed is a basic filter so leaves and insects don't interfere with the fan workings etc.

If you drove a human being nose-up at 70 mph for a few miles, I expect he'd have a few bogies to pick.

Waste of time, take it out and throw it away, you won't notice.

Purely a marketing scam.