Sacks touches succintly on policy. He seems to favor government measures to encourage the shift to fuel-efficient cars. Governments should help buyers of efficient cars with subsidies (or tax exemptions); maybe punish owners of gas-thirsty cars with higher taxes. Both sorts of measures involve coercion. Subsidies come from money that tax payers don't enjoy giving away; owners of inefficient cars will not find satisfaction in paying more taxes.
Apparently, Sacks believes that what works for him (voluntary action and personal satisfaction) will not work for others. In fact, he is willing to sacrifice the freedom of others to achieve the goal of reducing pollution.
(I wholeheartedly recommend the two books by Oliver Sacks that I have read so far: The Man Who Mistook His Wife for a Hat, and An Anthropologist on Mars. Both tell the stories of people fighting hard for identity and dignity in the most adverse circumstances.)