From 40MPG.org
Looks like the government is taking a bad idea and making it even worse. We’ve said from the start that the "Cash for Clunkers" legislation was a mistake. Now it appears the Environmental Protection Agency (EPA) is changing the fuel economy ratings of many older vehicles so some become ineligible and others that did not qualify before now do. It’s turning into a real mess for consumers, especially those who tried to take advantage of the legislation early now find they either have to return the new car or pay $4,500 more. 
The EPA review just took place over last weekend prior to the program launching July 27, so anyone looking to take advantage of the program should really do their homework first.
A thoughtful op-ed in the Christian Science Monitor sets forth a proposal to really boost fuel economy: offer automakers financial compensation for vehicles that exceed the CAFE standards.
Amory Lovins, chief scientist at Rocky Mountain Institute (RMI), points out: "Under the existing CAFE legislation, if automakers surpass the annual minimum efficiency requirement, then they receive ‘credits,’ which can be used to offset deficiencies in subsequent or prior years. But that’s not a carrot — it’s more like a stick painted orange! Consider that from 1995 to 2007, the Big Three’s combined CAFE never once exceeded the minimum standards by even 1 mpg."
