If your dog understands to stay in the car with some duration and distance, you can start to add distractions now.
Some distraction ideas are:
The training session in the video is not ideal (important to show those as well!) as the dog is failing too much. You should always aim for at least 80% success rate (maximum of 1 mistake out of 5 tries).
Make sure to introduce distractions gradually and at a rate where you dog can be successful 🙂