I am curious for instance as to why Clipper upgraded to a car 2 years younger, is it a question of going for the newest you can afford or are they changes in spec by a certain year for a model that make it much improved?
I think it can be a combination of factors ( God, that's profound, isn't it!0 For example:
4/4 cvh owner wants Zetec of Duratec power unit
4/4 owner wnats more mid range torque
Wings etc are looking a bit tatty and along comes car with superforms
owner's current car doesn't have alloy bulkhead and car only a couple of years younger comes along which has- perhaps easier to change car than get the bulkhead sorted
owner of 4/4 is a Vee8 nut and spanking Plus 8 comes along
There are loads of others. I think it was the point Boshly made- thinking about the what and why is an integral part of the process