Well, that's what we've gleaned from a CBS news story in the U.S.
Two would-be attackers in Linthicum, Maryland, approached a man who was talking to friends at a service station, both wearing masks and one brandishing a gun. They tried to steal his car from him, but the man had a trick up his sleeve - he could drive a manual.
When he informed them that his 2005 Volkswagen "had a stick shift" their brains' clearly had a melt-down, and they ran off.
So there you go - driving a manual car protects you from car jacking.