opportunity costs

The green car of the year is an Audi A3 TDI Diesel, but I'm not so sure this is the best car, really.

Audi A3 TDI Diesel

According to this Wired article:

The A3 diesel is powered by a 2.0-liter direct-injection turbocharged engine that puts down 140 horsepower. It delivers 30 mpg in the city and 42 on the highway. It starts at $29,950 and is available in all 50 states.

That's not bad at all, and it's exciting to see lots of new cars getting better and better gas mileage. But I think we have to consider the alternative opportunities when we consider a "Green" car.