Rubber that thin provides NO protection at all. Remember, this lightning bolt may have traveled 2, 3, or even 10 miles through the air on its way to the ground. An inch of rubber will not stop it. It will either penetrate the rubber or go around it. That's how it gets from the bike to the road. It just jumps from the metal rim to the pavement. Also, at the voltages involved with lightning, anywhere from 100 million to 1 billion volts, just about everything becomes a conductor.
Thanks for the explanation.
Nope - what's happening is that the metal skin of the auto creates a "Faraday Cage" and the lightning courses over the skin of the car to the ground --- avoiding the occupants.
IOW, don't hang your arm out the window!