Hi, I have finally taken the decision to buy a Tesla Model X. However, I am confused whether I should buy a brand new Model X 2020 Long Range, or a used Model X 2017 P90D with the same specs I want (tyres, seats) that I found in the market. Buying the used one would save around £40k, I am not very fussed about buying brand new, I just don't want to miss out on features by buying an older model, especially that I am under the impression that are a lot of enhancements year to year. I have tried to gather some information to compare but there isn't a lot out there. My questions are: 1- is there an official changelog (for both software/hardware) that would mention new features and other updates year to year. 2- are there any software updates that exclusive for new models (Auto Pilot/full self-driving capability is a big part of my decision to go for Tesla). Or since autopilot is heavily reliant on software then old model are similar to new models since they all receive the same software (I believe newer ones will have slightly better specs). 3- in Summary, what would I be missing if I buy 2016 model rather than 2020?