When lightning strikes your car and you're inside your car nothing should happen to you or your passengers as long as you're not touching any metal parts of the car when it gets struck with lightning.
The tires will insulate your vehicle from the ground and usually nothing will happen but sometimes the lightning could fry electronics in the car and shut your car down or could even start a fire in the car.
If possible you should get out of your car when a lightning storm is about to happen because you're much safer inside a building or your own home than you would be in the vehicle should it get struck by lightning.