At every 3000 miles or, at least, every 3 months, a few drops of light oil or lock lubricant should be applied to the hinges and latch assemblies of the doors, the 
Hood, and the trunk or the liftgate. On the same note, the door latch strikers should be applied with thin layer of grease to reduce chance of wear and to ensure free movement. This is also recommended to spray especial graphite lubricant on the door and trunk (or liftgate) locks.