A good few years ago I worked on a Costing The Earth for Radio 4 regarding this subject. The conclusion was that brands like Rolls Royce, Land Rover etc who's cars are still on the road 30 years later were easily the most environment friendly. Even the largest, most gas guzzling cars will struggle to use as much energy as it takes to create it in its life time.
The fact that the hidden stuff that goes into making it is never taken into consideration, from the steel making, plastic manufacture, air miles used transporting all the widgets from all over the world etc.
Anyway, off to get a coffee with my reusable cup....