Honda's approach is different. There's the Hydrogen fuel-cell powered FCX Clarity
http://automobiles.honda.com/fcx-clarity/
and this from their 2007 North America plan:
Product and Technology Innovation – Automobiles
By introducing new technology and more fuel-efficient products, such as the Honda Fit, the company maintained its industry-leading CAFE performance: 29.1 mpg for its combined car and light truck fleet in model year 2006.
Honda is targeting a further 5 percent improvement in its CAFE by model year 2010, along with a series of new technology initiatives:
• Next-generation Variable Cylinder Management (VCM) technology applied to the Accord V6 Sedan and Coupe and Odyssey in 2007.
• An all-new, more affordable hybrid vehicle to be launched in 2009, with projected annual sales of 100,000 units in the U.S. and Canada combined.
• A next-generation 4-cylinder clean diesel engine, meeting EPA Tier 2 Bin 5 emissions, to be launched in 2009.
• An all-new more advanced, efficient, and dynamically styled fuel cell vehicle, based on the Honda FCX Concept, to be launched in 2008.