Does mum need assisted living and how to convince her to check this out?

Mum is not capable to drive anymore but she still drives her car. She is in the drivers seat with all decisions. She is also violent and I have learned not to say anything about anything she does. She slaps me to show who is the boss and I can do nothing, just walk away from the situation and leave her be for a few hours. Mum thinks she does not have anything wrong and she changed her general practitioner many times over the past 5 years. She has memory loss. She gets herself into dangerous situations. But she will not admit it. A typical day goes like this. Like this morning. I arrived and had no time for a cup of tea and chat first. She had decided to go to her friend. She drove us to her friend. Her friend had seen mum last week for the first time after 3 years. Her friend told me mum deteriorated. Mother drove out of the driveway forwarded through next doors bushes, drove 4 miles in second gear to find out the friend was not there. She drove back in second gear engine making lots of noise driving way too fast. She nearly ran a red light but I told her stop red light. She hit the brakes and my neck still hurts from that. She pulled up with the same force when the lights hit green. She slapped me hard and told me that she is the boss and that will teach me not to tell her what to do. Nobody tells her what to do. I got out of the car at her house and just left. I did not make her tea today. No use as she thinks I poison her if she is not around to watch. She makes her own food. Now how would I convince her to seek some form of help? I think she would qualify for assistance but how do I bring this up?