I think to answer your question in the simplest form would be that more and more cars are going "green". A turbo'd 4.0 V8 isn't exactaly going to be doing it's part when it comes to emission and mpg economy.
We actually have a pretty modern and efficient powerplant in the 370 and for the weight compared to other cars (like that Canadian Camaro), it's leading the charge in power to weight ratio.
When all sorts of magazines and independent tests are calling it the "car of the year" and "best performance for the money", it probably stands to reason that the car isn't all that bad off.
