In the last hybrid I got a ride in, if you were drawing too heavily on the gas engine, the console backlighting would go from a soothing bluish-green to an angry red. Rather dramatic feedback, but I could feel myself responding to it - and I was a passenger.

There's a particular hybrid car out there that actually does have that if you drive outside of "environmentally sound" parameters... i.e. too hard of accelerations or high speeds. The idea is to encourage driving in such a way that maximizes your mileage, thus making the trees happy.

The first image that would come to my mind is the leaves swirling in my wake as I press the pedal to the floor around a fun corner (observing all proper speed limits and common sense, of course).

It seems that some designs are justified by people seeing a design they like, rationalizing it after the fact, and applying their rationalization in a way that is too general, without considering other ways the design could be interpreted.

I think it plays a scene of Bambi watching his Mom develop emphysema...=)