Ok, maybe if you buy only leased vehicles you could CYA enough. But this thread was about "used vehicles", no?

Oh, sorry, I misunderstood the nature of risk you're describing. You referred to lack of maintenance by the previous owner, I thought you meant lack of maintenance on the vehicle while on the lease. A good mechanic would be able to at least quantify the risk level on a used car, it seems, with X-point test that most of "certified pre-owned" places conduct.