Just the usual used car checks.
I bought mine (2016) used at 2 years and it had had a couple of recalls (USB supply, rear brakes). Some had a recall for a coolant leak.
Just had first MOT, no issues. Brilliantly put together cars, and they just work.
You could do the OBD2 thing but I expect you'll see 100% health, no doubt there's some battery degradation going on- but so far invisible to the user.
It's so good we have 2 of them
