Two remarks on this story.
1) TURN OFF THE KEY and remove it from the ignition slot, With newer autos, press the START button to kill the engine. Turn OFF the car!
2) I have twice driven cars for sale on a test drive in excess of 120 MPH with the salesman in the seat next to me. The only comment was along the lines of: ‘she’s a goer!’ (Porsche and Aston martin if you were wondering).
TURN OFF THE CAR!
IMO, not recommended. One time I had the engine die while I was driving on the highway. VERY difficult to steer with the power steering out and you had to stand on the brakes to slow down. Scary situation.