Sounds hauntingly familiar - we went through all of that with my mother. Taking away the car keys turned out to be easy. When she asked we told her the car was at the mechanics, and astonishingly quickly she forgot about it. Showers became a hazard as she would sometimes turn on the hot water full blast. Installed a locked temperature knob. The biggest hassle came when she started wandering off. The police would return her - she was found roaming the neighborhood, going to visit a friend (said friend had been dead ten years, and lived 40 miles away when she was alive - far too far to walk). When it started happening at night we had to move her to a locked care facility. Oy. She cried not to leave her there on that first night, like a child being left at camp for the first time. The second night was no better, nor the third, nor the fourth, but she did eventually settle in at the new place, though went downhill quickly. One day she simply refused to eat. No coaxing could get her to, and we refused to have her fed intravenously. And maybe two weeks after that, it was over. Her death was not a sad time; we viewed it as a time of release. This was a woman who was a trained nurse, a grand master at bridge, and ace at the NYT crossword puzzle, and a voracious reader, reduced to making belts woven out of leather strips in a day room. The woman who was my mother had been dead more than four years before her body finally caught up with her. A death I would not wish upon my worst enemy.