Eliminating your Jeep's factory spare tire carrier exposes the plastic/rubber factory cabin vent. Without your spare present, his unsightly plastic allows an increased amount of dirt/debris to enter the tailgate and can lead to premature rust & corrosion. Covering it completely, on the other hand, will affect cabin airflow when the top/doors are on and cause the HVAC system not to work properly. This JKS tailgate vent kit replaces the brittle, plastic factory vents with a louvered metal plate to prevent breakage, minimize the likelihood of interference from debris, and allow free airflow as intended by the factory design.