First of all, some things to state:
Montanna *DOES* have a speed limit. For awhile, after the federally controlled speed limit was lifted, Montanna's speed limit was "reasonable and prudent." However, it was very quickly changed to what it currently is (75 mph if I remember correctly).
As far as having no speed limit goes...it's only a good idea if you have the education to back it. It works in Germany because the driving tests are much more difficult. Give a driving test as hard as any county in Europe, and only 5% of americans would be driving.
Also, the deal with gas being expensive, yada yada yada. Suck it up. We are still cheaper than 99% of the world. I wish they would raise prices even more. It would get the people who don't like to drive off the roads. If it was $5/gallon, the only people driving would be people who like to drive (and who usually *can* drive).
Finally, the whole deal with car companies making SULEV's and ZEV's vs. SUV's that suck up a ton of gas...
The governement requires car manufacturer's to meet a CAFE requirement. The requirement is that the average fuel consumption of a product line must be at a certain point (I think the federal standard is 25 mpg). Any manufacturer who does not meet this requirement is required to pay a gas guzzler tax (such as Ferrari, Hummer, Lamborghini, etc). You know why the engineered the Chevy Corvette to get 26 mpg? It's because it counteracts the fact that the Tahoe only gets like 15 mpg. Chevy has to produce enough vehicles in their product line that average out the SUV's so that they don't have to pay gas guzzler taxes, because that is not a good way to attract customers.
Anyway, you guys should read up on
http://www.motorists.org (NMA) as well as
http://www.epa.gov (EPA) and look at information on speed limits and emissions.