I moved away to university and left my car at home. No one in my family drives but they've been starting the car and letting it run to stop battery from dying. However when they tried today the central locking wouldn't work. When they tried to open the car manually with the key, again it wouldn't work. The only reason I could see for this to happen would be the battery to completely drain? There is no key hole in the boot, so I can't get into the car that way to pop the bonnet. Is there a way to get into the car without taking a brick to the window?