[ctdonath]

Sounds silly to most, but there are situations where you don't want unfiltered outside air leaking in. If "seriously filtered cabin air supply" is relatively easy to add, there's no downside to adding it. Here around Atlanta, the pollen count can exceed 5000 for weeks (and 500 is considered "extremely high"); a good filter would be dearly appreciated by many. For an interesting comparison re: "bioweapon", consider the armored luxury car market with product features such as http://www.caratsecurity.com/Products/sedans-and-SUVs.php

[raisedbyninjas]

It's not silly at all. I wish I had this everyday that I'm sitting in traffic. My car has multiple climate control modes that default with the vent open. Some heater modes override the vent button and force me to use outside air. I actually know what the outside humidity is and the amount of car exhaust I want to suffer. But apparently that doesn't matter to Mazda.

[wang_li]

If you don't have a steady flow of outside air into your car's cabin, you will soon die.

[ctdonath]

The point is there's a difference between ambient outside air leaking into the car like a sieve, vs completely sealed with air supplied via biohazard rated filtration. Also, you'd be surprised how long you can function fine in a sealed box the size of a car cab.

If you haven't seen waves of pollen wafting thru the air for miles, like we regularly see near Atlanta, you may not grasp the interest.