Serious questions though:
Are there differences between the lithium batteries in these things that keep catching fire and the ones used in cars? If yes, what?
Basically two main types in vehicles, but unlike E scooters and bikes battery management and safety is way better, yes there are fires and as the sales of EVs increase so do the fire rates increase (but not going there)
If not, can the average used car buyer tell whether or not the battery of the car he or she is looking at has been messed with?
In most EVs the battery cells are the make up of the chassis and are encased by it, here in the UK there are four levels for a tech to achieve, the small number that have passed only take three, (bloody hard) a lot of physics involved.
At level one the first modules cover shutting the vehicle down to make work safe,(for routine servicing/ maintenance) this procedure takes two qualified techs with special PPE one looks after the others safety.
You would have to be crazy to try and mess with an EVs electrical system unqualified, but like everything else it has been tried resulting in several back street spanner swingers loosing their lives and at the least loosing limbs after being zapped with pushing up to nearly a 1000V.