"You mised my point about car fuel economy - car companies in the past complained that they would go broke trying to meet newer standards of fuel economy, just like all the complaints today about the economy tanking if Kyoto or similar reductions were to be attained. The car companies - at least the smart ones - are thriving, and so would many areas of the economy should CO2 and other emissions be reduced effectively."

Car companies did go broke. They also charge a hideous amount of money for cars. A reasonable price for modestly priced car should be about $5000, but you paying about 3 times that.
Was it worth it?
My new VW bug which cost about $2500 back in mid 70's had comparable gas mileage as today's cars. Today's cars on average are better- e.g. much longer lasting engines. But in 30 years you could expect this level of improvement and lowering cost to happen. For instance look at car tires- much better than they were 30 years ago and cheaper if you allow for the dollar inflation. So buying a new car today for $5000 would cheaper than mid 70's allowing for inflation, but that would "normal" compared to other products [electronic products, obviously has improved, but even comparing thing like refridgerators, washing machines, ect]. And it's likely that this $5,000 car would better than current cars- better gas mileage, as safe or safer, and better selection of types of vehicles. Take out all the lawsuit bullshit and all the unneccesary govt reg, and we probably would have had flying cars- sure they might be pricey like say, $40,000.

Today there is less competive forces due to govt laws, and therefore one can expect that cars are going to get more expensive and less improved. China might change that, but it's unlikely with the current Chinese political situation.