My Dad is 91 next week he has Alzheimer's and mixed Dementia. He had to stop driving at 88 after taking a DVLA test and failing. He is now getting very agitated, and annoyed when I tell him he doesn't have a car anymore, and that he had to stop driving, and we sold the car. He doesn't believe me, or any of the family. I really don't know whether to agree with him and say he has got a car??? Just what to say to calm him.and He keeps getting up and saying he can take me to where he parked the car! Does anyone have any suggestions please?