Use Clear Silicone Spray ( No white residue and nothing to collect dirt over time to cling to the grease and cause a sanding effect on the surfaces. Spray the hinge well, soak the areas with spray while moving the door in and out. Just put a rag down to catch the drips. You will notice it will also free up any dirt and grit in the hinge. Once you are done, you just wipe everything down with a clean rag, take your time and get in all the nooks and crannies, it will look like it just came from the showroom. You can also use WD-40, but I found the silicone does not leave a wet film to collect more dirt. I also wet a rag with the stuff and wipe down all the rubber seals around the doors and rear hatch. This helps in the cold climates so the seals don't stick to the frame when they get wet. Also gives them a little shine and protects them from drying out. Twice a year, your good to go....