If you take a small, cheap, functional and basic modern car like a Suzuki Wagon and compare it with cars of 30-40 years ago when I was first unleashed on the roads it is quite interesting. The wagon is "unstylish", "slow" and has poor "handling" by modern standards, yet it out-performs my old MG and Minis in every respect (apart from torque). Better acceleration, road-holding, top speed, braking, fuel economy, reliability, comfort, emissions, quietness, space, stereo radio/CD player, heating and ventillation etc. However, the amount of components and materials used to make it is enormously greater, and a large part of that is all the plastics used for bumpers, interior fittings and all the insulation on all the extra wiring to operate all the gadgets which are now normal, even on budget cars. Our bubble cars and micros are not all that green in some respects, but they do provide sheltered transport with a minimum of materials, meaning that their impact (spread out over the years of their life) is not too bad.
Now look at huge and heavy modern Executive Saloons, like the big Mercedes Benzes and BMW and just look at how much material and components goes into one of those! MB make all sorts of claims about efficiency and green credentials, but does it REALLy need 3 tons of material and dozens of gadgets to transport one man and his brief case to the office and back every day?!