[freebeard]

Just A Car Guy: did you know vehicles radiators can be coated with an ozone reducing catalytic coating? Manganese oxide, a catalyst, not consumed during the conversion of ozone; therefore the catalyst’s lifetime is extensive, usually several years.

as it drives along, it reduces ozone, a component of smog, capturing about 75 percent of ground-level ozone and converts it to ordinary oxygen

The New York Times had an article on it in 2000

in the 1990s, Volvo worked with New Jersey-based catalyst company Engelhard to use the radiator as a sort of "filter" for smog-producing, ground-level ozone that passed through it in a system called PremAir.
....
Volvo's PremAir coating, the representative went on, only added about $50 per car...

One wonders how much it would cost as an aftermarket add-on. Can it be refurbished after 'several years'?