Backing
Secondary Backing – Newer vehicles often have a sound deadening layer added to the molded carpet. This layer is called "auxiliary support" and exists for several reasons. The most obvious benefit is the further reduction of annoying noise associated with the vehicle floor, such as tire noise. The heavier backing also makes the molded rug more crisp and detailed. Another benefit is that it acts as a secondary backing to reduce or even eliminate liquids such as melted snow or spilled drinks from contacting the floor and causing unnecessary damage to the metal underneath, and lastly it is perfect in terms of stability.