[alasdair_]

>Cars are versioned by year/model, which again makes it pretty clear to understand minor/major updates. Sometimes significant updates are introduced in a model year, but generally the core features remain the same and it could still be considered an upgrade to that model.

Tesla managed to break this trend massively, which proves a problem for things like insurance. The feature set on (say) the January 2014 Model S is very different from the December 2014 Model S, even though they technically share the same "year".

[mirashii]

Tesla didn't break this any more than any other car manufacturer. The model year hasn't been tied to the manufacture year for a long time. See https://www.autotrader.com/car-news/why-doesnt-cars-model-ye... for instance.

[hakfoo]

I think the difference is more "model year no longer reliably indicates feature set", not "model year no longer indicates date of manufacture."

This may make finding and pricing spare parts difficult, or categorizing safety and performance metrics.