It takes about the same amount of material to make a BMW as it takes to make a Chevy. The only real difference is the design.
John Barrie, an architect who has taught at the University of Michigan and Washtenaw Community College, admits that perhaps there are other minor differences: (Ok, some of the interior finishes in a BMW may never be seen in a Chevy, but bear with me) but notes "The shape, color, texture and even the sound of a new car are designed and built from the same lump of clay. The same holds true in Architecture. The same pallete of materials handled by different Architects will turn out differently." He continues with some wonderful suggestions for building sustainable homes. Read more at ::Sustainable Design Update