[myst1q]

Like a catalytic converter, a chemical solvent or absorbant (of course, capable of absorbing all the bad gases) could be designed and attached to the exhaust system of any automobile. This also can have an air quality meter so that the exhaust's pollution level can be measured and controled.

This would make the air we breath cleaner and safer.

Reward: Better Earth for younger generation to live

[The_Wise]

This sounds like a reasonable idea, but what happens with the chemicals that have absorbed the gases? The gases don't just disappear, you would then have to dispose of the chemicals and then replace them.
Catalytic converters are put in cars because they don't need replacement and release a relatively less toxic oxidised nioxins and carbon dioxides into the atmosphere.