I can see whacking a guy three times with a Miata to kill him, but once with a Benz should be enough.
The woman is trying to uphold standards of thoroughness, which are all too lacking in you young people today. Besides, you whack a Dentist with a Miata, it's the Miata going down, not the Dentist.
After reading this by the way, I rushed out to Pep Boys and got those two little siren gizmos you put on your front bumper to frighten deer. I am going to do a study to see whether or not they work on dental personnel. Inquiring minds want to know.