There are a few things you can do to stay warm in a car homeless. First, make sure your car has a heater. Second, put some blankets or towels on the floor of the car to keep you warm. Third, try to find a place to sit or lay down so you can keep your head and body warm. Fourth, if you can find any kind of fire, try to set it up and keep it burning. Fifth, if all else fails, drink lots of fluids and eat some food that will help you stay warm.