A flat tax is regressive and punishes those with less money.
Instead, let’s provide a reasonable ration of gasoline for each individual. Under this plan, rational gas consumption becomes a 100% tax-funded commodity. Each individual is awarded a reasonable number of gas credits and no more. If you need more gas than that (for your Hummer for example), you can buy on the spot market, which the government can tax the crap out of if they want because REASONABLE Americans who actually want to participate in a SUSTAINABLE energy policy will be shielded from the direct effects.
Under this plan, individuals can buy and sell their credits, which expire at the end of each year. Under this plan, Americans who use less gasoline will benefit MORE, because they can sell their credits for just marginally less than the official taxed-the-crap-out-of rate the government is selling fuel for.
People who never drive at all will likely make money under the plan, even if they are taxed at 100% of the cost of the credits.
If anyone is worried about the risk of deflation, we can set up an FDIC of sorts to cover the value of the credits.