The rear box lid can be wiped down with a wet towel during regular maintenance to prevent salt creep. If you find that you are getting salt creep on the outside of the rear box, then take the lid off the box and dry it completely. Use the below Silicone grease and squeeze it inside the small channel of the edge of the lid. Make sure to put it all the way around the whole lid seal. This will 100% stop any salt creep from exiting the rear box.