Which they should because they’re often the leasing company
Not sure I follow.
If the car is doing a n extra 2-7k pa it'll only become apparent after 5yrs or more, by which time it'll have been through a couple of leases and sold by the manufacturer.
If the speedo and ABS etc still work it should be trivial for the computers to detect something like that. Unless the manufacturers don’t care.
(Which they should because they’re often the leasing company)