On a UK site I found info on the pollen filter. It is or is not supplied with the passion. It is a charcoal filter, non hepa. It is located on the right side under the bonnet. As you face the front of the smart that would be the passenger side for a left hand drive. In the USA we would say on the fire wall. (old fart talk) Apparently it has warning stickers so you don't loose your digits due to wiper activity. Pop the clips and you should see a pleated white/gray filter with black spots of charcoal directly inside. If not, you have no filter and need to chat with the good smart folks, should you chose to filter the pollen, dust/dirt, pine needles, ear wigs and any other thing that can crawl or drop into your vents. Please only buy one or two per customer as I have allergies and don't want to be left out if and when I get my passion with out a filter. They are supposed to last a year. Those with allergies will know just how effective the filter is and hopefully post their results.
It if sucks or is just stupidly way over priced. This maybe my golden opportunity to invent and sell my own. Allergy sufferers unite!
Please post prices.