Obama: Seems to be a 'Johnny come lately' regarding the environment and fuel efficient cars. Has no serious record prior to running for presidency. Gave up his gas guzzler in Oct2007 after he realized it was politcally incorrect. I haven't heard too many specifics from his speeches on what he will do, generally he claims he will just support the developement of better cars and ethanol, yadda, yadda. He does want to change the tax credit for hybrid vehicles so that there is no cap by manufacturer.

Hilary Clinton: Seems to have a longer track record than any other canidate and has put forth specific plans to advance fuel efficiency and energy independence.
From http://www.hybridcar.com/index.php?opti ... 1&Itemid=2
Investing $2 billion in hybrid car battery research
Adding 100,000 PHEVs to the federal fleet by 2015
Offering consumers tax credits of up to $10,000 for purchasing a plug-in hybrid

John McCain: Inadvertently he could be the greatest proponent of fuel efficient vehicles and reducing green house gases. He is a firm believer in nuclear power as the main way to energy independence, something no other leader would dare say, even though its the only realistic solution. The next generation of plug in hybrids will need to get their electricity somewhere's. McCain would supply those plug-ins power from nuclear power, thus reducing foreign oil dependency and eliminating green house gas production.
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Staff, Car Repair Ratings, http://www.carrepairratings.com