Polaris RZR-900 XP-1000 Door Insert Kits. Door Inserts for the Polaris RZR 900 S / XP 1000, constructed from a powder-coated mild steel tube frame and plastic skins. We use a top quality thermoplastic high-impact polypropylene which offers a high-gloss finish with excellent durability and is available in several colors. Why pay double for the OEM insert offerings when you can have quality made in the USA products from Factory UTV. While not designed to be water tight, these inserts do help a great deal in protection from from the elements and greatly enhance the RZR s looks. These door inserts are a quality upgrade for your RZR. Count on Factory UTV Accessories, your number 1 UTV accessory supplier.