For fender benders or even total car writeoffs, sure. But for fatalities? From my admittedly narrow and predominantly first-world view that doesn't sound plausible.
I saw two fatal accidents in Vietnam in the three weeks I was visiting. This wasn't unusual, other tourists saw similar numbers.
I'd guess wealthy drivers simply paid the deceased's family (and the police if necessary), or in other cases the pedestrian or cyclist was blamed entirely and the accident not recorded as a motor vehicle accident.