This is great! We should be starting to look at net-negative carbon solutions. Even if it's only a little bit, with the amount of cars on the road this sort of thing will add up. If the filter or capture device is unpowered or only uses the kinetic energy of the air it's pushing through that's even better. Hopefully it's not something that takes a lot of maintenance too.

I love the idea of turning all those little sources of carbon emitting terraforming cars into carbon sippers as part of an overall solution!