The doors, 
Hood and trunk hinges and latch assemblies should be treated with a few drops of light oil or lock lubricant every 3000 miles or every 3 months. Also, the door latch strikers should be greased, but thinly to avoid creating thick layers of grease on them while enhancing their operation. It is also good to grease the door and trunk lock using the spray on graphite lubricant together with applying astroturf on the interior door handles with grab handles.