Will Prius stay on if key away from car?

No, a Toyota Prius will not stay on if the key fob is moved outside of the vehicle's range. The car is designed to detect the presence of the key fob for its operation, and once the key is out of range, the vehicle will eventually shut off to prevent unauthorized use. If the key fob is out of range for too long, the engine will turn off, ensuring safety and security.