Door Panel Vapor Barrier
Some have suggested that your local hardware store has it but this is made for landscaping.
Door panel vapor barrier. I believe this is what alprada70 here on the forum uses to form his vapour barriers but i let him chime in. Laying out the plastic an cutting. It provides a degree of water protection to your inner door and is designed as a vapor barrier. The vapor barrier keeps the odd drip from the window from splashing on the window mechanism and wetting the speakers and other electronics in the door panel but if you are getting enough water to wet the carpet there must be a blocked drain hole.
It tears easily and if it is reinstalled with a tear an interior water leak can develop. It is used almost on virtually all new cars. The right choice can elevate the inside appearance of your grand cherokee. Common door panels are plastic and these are a great choice when you need a quick serviceable replacement.
I suggest having extra door panel clips on hand before removing the panels as the clips can often break when removing. Some prefer wooden panels for their beauty and style to improve or customize the inside of their jeep while others opt for the look of sheet metal door panels. Attaching the barriers to doors. It is installed between the door panel and the door.
Where to get the plastic. Be very careful when removing the vapor barrier. If you have to remove the vapor barrier have vapor barrier sealant on hand. It comes in a 12 feet roll and is shipped in a 3 inch tube for protection.
Another option that acts as both water barrier but also reduces some noise is closed cell foam sheets. This is a universal fit paper shield with a black plasticized film on one side.