Inside a car. The reason your vehicle is generally a safe place to be in a lightning storm is not your rubber tires—it’s the metal frame of the vehicle, which can act as a Faraday cage, directing the electric current around the outside of the vehicle. Most vehicles today are made with enough metal throughout the frame that you will be protected from lightning should it strike your vehicle, provided you’re not touching interior components like door handles, gearshifts, electronics, or the steering wheel.

Source: AMA