This chart is fascinating but seems somewhat devoid of the reality of marketshare, price, regulations (safety, taxes), etc. Tracking a particular set of car mod

This chart is fascinating but seems somewhat devoid of the reality of marketshare, price, regulations (safety, taxes), etc. Tracking a particular set of car models and talking about how they have evolved over time is only relevant if the marketshare is similar and the demographics of the customers are similar. If the average selling price of a particular a "compact" car has increased in price (relative to inflation and the market) by 2x and it's gotten .5m longer, is it really the same car segment anymore? Just because it has the same name is it the same thing? Another aspect which is fascinating is how neatly these mythical segments all increase in length over time. The reality is that for any given year, there are a variety of sizes of car for sale. Do we look at a scatter plot per year of length vs price, or length vs engine displacement, or length vs marketshare? There are so many ways to slice and dice the data. The auto industry has also been predicated for years on the concept of planned obsolescence. Each year the new model of a particular car needs to get slightly "better" in some way. Bigger, better (more "luxurious"), faster.... The overall average of all of this may be essentially similar. The graph reminds me a bit of a Shepard tone. It's an audio illusion where a sound seems to be constantly rising in pitch, but on average it's actually staying the same. https://en.wikipedia.org/wiki/Shepard_tone https://en.wikipedia.org/wiki/Shepard_tone