This form of dementia makes it impossible for his brain to perceive there is anything wrong. Thus all attempts to get help like Visiting Angels or a caregiver are met with complete refusal and dismissal because he is "just fine." He is still driving (!) and really should be in a home or have a caregiver. Is the only answer to have his daughter get guardianship through the court and then make a decision to move him against his will? He will never understand there is a problem.
You cannot convince someone with anosognosia OR dementia of anything, so stop trying. His daughter needs to do what you said, or report him to APS as a senior with dementia living alone and THEY will place him. But in the meantime, his car MUST BE REMOVED. Please do the right thing.
I would start with questioning APS who may be able to help you in getting Temporary guardianship if person is (and he IS) a danger to self and others.
He is never going to accept he has dementia, so give that up.
I would advise you to read, Google and learn anything and everything about dementia you can.
You need to find a way to get the keys away from him. That's utmost important!!!!!