IMO the big 3 have their heads up their asses.
VW has said they aren't going the hybrid route and IMO I believe they are going in the right direction using some thinking outside the box. (at least right now) They have been working on their diesel stuff and now they are using a supercharger/turbo combo to get the job done. VW is using 1.4L that perform like their 2.3L and get 20% fuel mileage.
http://www.greencarcongress.com/2005/08/inside_vws_new_.html Heres the scoop, USA has a corn & soy fetish, (ethonal & biodiesel). USA wants zero NOx, thats hard to do using diesel.
European Union favors the 4 & 6 cylinder turbo diesel engines, low CO2, better engery efficiency, MPG, less fuel consumtion.
This is more a political mandate and the big three have to comply, which hurts the consumer, higher price cars, less MPG, less torque, less power. And I do think VW, BMW, Audi has it right, small to mid size turbo diesel engines for the autos.
Here is an example, a BMW 730d can go 650 miles on a single tank of fuel. 35 MPG at an average speed of 76.8 mph, 4,300 pounds, powered by a 3.0-liter straight six diesel. How about the Audi A8 4.0 TDI, twin turbo, V-8 diesel. 479 foot pounds of torque at 1800 RPM's, very fun to drive. Or the new beetle TDI, 49 MPG.