I thought this was a decent proposal of legislation by a rep in Congress...wish one of the heavy hitters would sign onto something like this: 
Congressman Proposes Tax Credit for Plug-in Hybrids and EVs
26 March 2007
US Representative Dave Camp (R-MI) has introduced new legislation that would provide individuals and businesses with a tax credit for the purchase of vehicles with larger battery packs, such as plug-in hybrids or battery electric vehicles.
To qualify under Camp’s proposal, a vehicle must have at least a 4 kWh battery pack. The credit would be the lesser of either 10% of the cost of the vehicle or $4,000 plus $250 for each additional kilowatt hour of battery capacity above 4 kWh up to 50 kWh.
Camp, who authored existing tax credits for hybrid vehicles, said the new credit would add incentives to manufacturers already exploring the viability of plug-in vehicles.
Unfortunately, new technologies always cost more at the start. My tax credits will help put the cost of hybrid electric vehicles more in line with their traditional, gasoline counterparts.
Our domestic auto manufacturers are already working on this technology and we cannot afford to have the government playing catch-up in this area. In order to maximize the benefits of the new, clean technology, it is important to have these tax credits available the day these vehicles hit the salesroom.
—Rep. Camp
In order to appeal to varying automakers, the bill does not discriminate between types of plug-in vehicles such as pure battery electric, extended range electric, hybrid electric and plug-in fuel cell vehicles.
GM, Ford and Chrysler all have revealed plug-ins at various stages of development; Toyota has indicated it is working on a plug-in.
DaimlerChrysler has the Dodge Sprinter plug-in parallel hybrid, currently in road testing (earlier post); General Motors is working on the Volt plug-in series hybrid (earlier post) and its E-Flex architecture; and Ford is researching the Edge plug-in series fuel-cell hybrid (earlier post).
http://www.greencarcongress.com/2007/03/congressman_pro_1.html#comments
Congressman Proposes Tax Credit for Plug-in Hybrids and EVs
26 March 2007
US Representative Dave Camp (R-MI) has introduced new legislation that would provide individuals and businesses with a tax credit for the purchase of vehicles with larger battery packs, such as plug-in hybrids or battery electric vehicles.
To qualify under Camp’s proposal, a vehicle must have at least a 4 kWh battery pack. The credit would be the lesser of either 10% of the cost of the vehicle or $4,000 plus $250 for each additional kilowatt hour of battery capacity above 4 kWh up to 50 kWh.
Camp, who authored existing tax credits for hybrid vehicles, said the new credit would add incentives to manufacturers already exploring the viability of plug-in vehicles.
Unfortunately, new technologies always cost more at the start. My tax credits will help put the cost of hybrid electric vehicles more in line with their traditional, gasoline counterparts.
Our domestic auto manufacturers are already working on this technology and we cannot afford to have the government playing catch-up in this area. In order to maximize the benefits of the new, clean technology, it is important to have these tax credits available the day these vehicles hit the salesroom.
—Rep. Camp
In order to appeal to varying automakers, the bill does not discriminate between types of plug-in vehicles such as pure battery electric, extended range electric, hybrid electric and plug-in fuel cell vehicles.
GM, Ford and Chrysler all have revealed plug-ins at various stages of development; Toyota has indicated it is working on a plug-in.
DaimlerChrysler has the Dodge Sprinter plug-in parallel hybrid, currently in road testing (earlier post); General Motors is working on the Volt plug-in series hybrid (earlier post) and its E-Flex architecture; and Ford is researching the Edge plug-in series fuel-cell hybrid (earlier post).
http://www.greencarcongress.com/2007/03/congressman_pro_1.html#comments
