Me too! I would also eventually like the biodiesel option. Right now government regulations make it difficult to sell diesel engines in passenger cars. There's a new VW diesel over in Europe that can get around 67 mpg. Nice. From what I hear they are on their way and it's only a matter of time. Additionally, running biodiesel from say cellulotic or algae sources is much cleaner than running normal diesel (not just the CO2) so I hope the government relaxes on the regulations. Thus, Hold on. Won't be in Volt 1.0 but who knows after that.