We might have a little bit of different ideas about masks, and I don't really consider them to be necessary when outdoors (especially if no one is around) or if you are in your car by yourself, so I have seen people wearing masks in those circumstances, and just seems to be overkill to me, but of course a personal choice, and great that they have masks, and I understand that if someone just gets used to wearing a mask a lot of the time, then maybe they will fidget around less with it.
lotta cars have HEPA filters on the fresh air (cowl) intakes now. unsure what the rating is though.
check the manuals for your wheels.
and of course you need to know how to set the hvac controls correctly, including allowing for exhaust direction due to windows being open etc. rtfm dyor
maybe they are not enough, unsure but hey look it up for your make and model.
Personally I'm not worried in my car or outdoors in general. Studies show this thing is mainly spread by closer contact so I gear up when going into a building or talk to a person closer than 6 feet (say like yesterday at the dump). No sense wasting the filters, and even though the respirator is really comfortable it's annoying to wear constantly (they are however designed for workers to spend 8 hours around asbestos/lead dust, so they are pretty nice)
Teslas have a NBC mode where the outside air is filtered then pumped into the cabin under positive pressure to keep cracks and seal leaks to a minimum. That to me is a bit much, and it can take a *month* to charge a Tesla from a 1kw solar array.
One big advantage of this virus over nuclear is that leaving the mask in the sun will kill the virus particles accumulated in the filters. This is a good thing.
Meantime, this is funny: