What's sad, really, is that there's a ton of cars that were sold with HUGE state tax rebates (like $10,000) because they were dual-fuel, and in theory could be run on propane or gasoline. NOBODY runs them on propane, and they're almost all huge trucks and SUV's that get about 15mpg. Still, they get the alternative fuels license plates and can use the carpool lane legally. That's a scam if ever there were one.