My first article here and I wanted to really help you guys with something I researched over the last 5 years and which is important for our health but generally skipped by the car maintenance guys every single time, even at the dealership.

We know we live in a polluted world, we know that climate change is true and that microparticulates affect our health and help cause cancer. So for the last five years I tried to find car filters that help filter the danger out.

I live in Europe and I drive a VAG Group car (Volkswagen,Audi,Skoda,Seat, Porsche), which has the same air filters as the most VAG Groups cars so my review should apply on all cars that can fit the filters ( even Ford,Mercedes and so on )

First of all be sure that the filter is changed, because a dirty filter means no protection no matter how good the filter is:

I used the original part which is not anything amazing, exhaust from other cars comes in, smells from the occasional garbage dump truck and polen. This was a simple filter that was dirty-black when i changed it.

I then used a couple of carbon activated filters which did very good, I couldn't feel any foul smells anymore inside, but when driving near chemical plants instead I could feel the smell of carbon from the filter. This meant that microparticulates passed the filter taking some of it's carbon with them.

I then did some research and found out about the PM10 or PM2.5 filters. Nobody at the dealership knew about the research or about the filters, not even the engineers, not even the Porsche dealership service support.
I had to contact the air filters manufacturers and found out that there are filters but obviously they have a hard time marketing them since only service engineers choose the filters and not ourselves.

http://www.mahle-aftermarket.com/media/media-global-&-europe/video/mahle-cabin-air-filter.mp4

I have found the following manufacturers having these filters:

1. Mahle and Knecht - http://www.mahle-aftermarket.com/eu/en/products/filters/cabin-air-filters/index.jsp#properties
They name this series CareMetix
2. Mann - https://catalog.mann-filter.com/EU/eng/vehicle/MANN-FILTER%20Katalog%20Europa/Vehicles/CARS%20%2B%20TRANSPORTERS
They name this series of advanced filter FreciousPlus and product ID's start with FP
3. Valeo - https://www.valeo.com/en/cabin-filters/   - they market them as  ClimFilter™ Supreme
4. Bosch - https://www.boschautoparts.com/en/auto/filters/hepa-cabin-filters - HEPA Filters

There may be others, but these are the ones I found and there is no order to that list except that i own a CareMetix filter and i am happy with it. No exhaust smell enters the cabin no matter what old style tractor is in the front :D

If  i raise some money I am thinking of buying a PM2.5 sensor from AliExpress to do more followups as this is something I see very important to all. I spend 2-3 hours in traffic every day and this seems to be peak of my exposure to pollution. I would like the car manufacturers to pay more attention to the filters they include in the cars; by the way Thanks Elon Musk from Tesla for already doing this even though not anyone can afford a Tesla :  
https://www.tesla.com/blog/putting-tesla-hepa-filter-and-bioweapon-defense-mode-to-the-test

I will update this article as soon as i find out more or do some testing. I already added Steem to my investment portfolio so I will be here for a while :D