My 87-year-old-father has dementia but still insisted on driving. If we have Power Of Attorney can we legally take his car away?

If you do not have gardianship or other legal order of control and that does not just mean a POA, then no you can not do anything. He has to be declaired incompitant! Otherwise you can do nothing except try to get him to sell or ? the car on his own hid my moms keys so she would not drive, alcahol dementia and drinking and she would take off, not sake for anyone. But legally I was stuck. Good luck, hang in!