A method of producing contoured vehicle floor mats having integrally formed nibs. The sheet is formed by a nib forming roll in an extrusion roll stack having a plurality of indentions. The nibbed sheet is placed onto the thermoform mold with the nibs directed away from the mold. The sheet is heated to a plastic state and stretched over the mold to form a contoured mat shaped to vehicle within a vehicle compartment, trunk or cargo area. The nibs on the underside of the mat contacts the floor covering and prevents the mats from sliding on the interior surface of the vehicle.