Well I'd certainly agree that an abundance of caution when buying any car is the way to go, but my experience of main dealers over the years has been patchy to say the least. I don't know how much of a thing independent battery testing is at the moment but I would guess that would be the way forward if folk are to have any confidence in used purchases of EVs.
I have to say, I know loads of folk with EVs but I'm struggling to recall a used purchase amongst them.
Of course EVs, like any electronic device, are fiendishly complex but I've not a clue what that complication translates into in terms of reliability and maintenance. It's also easy to forget how complicated ICE cars are - my brother-in-law is currently two months into an ongoing battle to find out what is wrong with his 2016 X-Trail diesel (according to the diagnostics: everything) and has already spent a lot of time and cash on work that was confidently predicted to solve the problem and has not. Is it the DPF? The EGR? The air intake sensor? We're about four garages in and nobody really knows