Abstract: Methods and apparatuses for decreasing automotive drag in vehicles are provided herein. In embodiments, a vehicle underbody airflow modulator may comprise one or more flexible panels and fasteners. A flexible panel may be retained below the underbody of a vehicle, covering one or more features of the underbody and preventing disruption of airflow by the features. In some embodiments, a tensioning device may be provided to tension the panel. Various embodiments may permit access to the vehicle underbody, dampen road noise, and/or decrease high speed vehicle lift, and may be made available at a lower initial cost than current alternatives.