So just an observation, take it for what it is worth. Most of us- apparently are somewhat grounded in the old school fundamental concept of the overall mileage, condition, rarity, color, engine, transmission and suspension, etc as the determinants of used car value.
I think for today's world we are wrong - or becoming much less correct. Here's why: think about all the new car ads for the past 8 to 10 years. All they are touting is electronic systems, computers, integrated entertainment, bluetooth and GPS, etc. NAV, blah blah blah. You already know what it means when one of these things shits the bed today. Replacing one of these cost more than the frigging engine ! *if you can get the parts at all*
We are largely fooled into thinking that only the moving parts fail-I have first hand experience with the really bizarre stuff that crops up when electronics fail, partially fail, or make you wish they would stop messing with your sanity. Add into that possibly deployed Airbag expenses or airbag control units and you have a situation where nothing essential ( in reality ) to the vehicle causes a 90% depreciation regardless of mileage or the condition of the fundamentals of our past. So I really question the fact that values are still so hinged to (mechanical) mileage numbers. Today, the health of the electronics is so much more a real $ factor and the manufacturing economic reality is they are not built to last as long as the rest of the car- add in a few manufacturing defects ( bad solder connections) along the way and all the wunder-gadgets become expensive paperweights.
Worse, so many of these systems are so integrated into the vehicle that the once simple swap out repair of a single electrical component will not work, its a system with configurations, firmware and software which the manufacturer may no longer support. Third party repair shops have little hope dealing with proprietary software.
My opinion is that the car world still does not properly price this into a used car.
The car buying public still has no concept of the cost to repair or replace these widgets. $$$$
Many car lots are not thinking of the time bombs these systems represent financially.
Auction cruisers are still spend more time listening to the engine than making sure all the features work.
The issue is only going to get worse in a logarithmic fashion as more and more fully loaded technical wonders hit the used car market.