A major advantage of methanol is that methane, its raw material form, can be mined and is already produced by the U.S. cattle farming industry. Methane, a greenhouse gas, is dangerous in the atmosphere and contributes to global warming. Harnessing methane contributes to solving the energy problem as well as puts a dent in our pollution levels.
Unlike hybrid cars, methanol could be a completely domestic industry, and not cost the environment in international transportation between manufacturing plants in the way hybrid vehicles do.
The disadvantages of methanol are similar to the ones found in ethanol production, namely that it requires the sacrifice of food resources in order to have an effective harvest. Cows bred for high methane output have inferior meat and milk, and since meat and milk is really the only realistic way to make a mass of cows profitable, farmers would be taking a massive risk in breeding cows for higher methane output, and therefore the cost of beef and milk would rise, harming lower and middle class families.
Also, because methanol is less volatile than gasoline, it would be more difficult to start a car in cold weather, which would inconvenience people that live in areas with snowy winter climates.
Methanol is a viable alternative because it can be cheap and efficient to recover and convert, but it can also be incredibly expensive if we run out of methane fields from which to harvest the crystalline form.