These areas include the tips of the door hinges and latch assemblies The car's doors, 
Hood, and trunk should, therefore, be opened, and a few drops of light oil or lock lubricant applied every 3000 miles or every three months. The door latch strikers should also be greased with a thin coat of grease so as to minimize on wear and allow easy movement. Also, spray the graphite spray-on lubricant on the door and trunk locks while applying the same to the hinge bolts.