So actually I don't see how they compute the "needed" sales! For example why do we need more 19.6MPG (almost double) luxury sports cars. I can see maybe that the reduction large truck might only be compensated by buying more small trucks. Nevertheless I'm puzzled. For me the bump chart doesn't work very well I don't understand whether the colors have any meaning (efficient/inefficient, differentiation?). Nor do I manage to connect the lines with the car groups (esp. the large group of cars in the lower third).

gary, distances are difficult. they are not well defined. do you mean the distance between racers when the first crossed the line or vice versa. further, the distance of second to first might be greater then that of third if she was really slow at the end. skiing isn't about how far do I get in a given amount of time but how long does it take me to race a given course. mathew, as kaiser already said, percentages provide a different perspective. i think they would only be informative if the amount of seperation between finishing times would mostly be on the length of the course, otherwise longer courses would simply appear more crammed at the top than shorter ones. from my experience, beside length, the amount of seperation is also largely dependent on difficulty of the course and stability of snow conditions. all in all i think seconds are just fine, they are the units that count, everything else would already go into modelling.