<p>Enhancing downforce often incurs a drag penalty, presenting a trade-off in automotive aerodynamics. Accordingly, this study systematically investigates the effects of front splitter height and length on the aerodynamic performance of a DrivAer fastback model using computational fluid dynamics (CFD). A parametric analysis reveals that overall vehicle downforce is primarily governed by splitter length, whereas aerodynamic drag is most sensitive to air dam height. Flow-field analysis shows that although the local downforce generated by the front splitter increases approximately linearly with splitter length, the total vehicle downforce exhibits a converging trend owing to counteracting lift contributions from the upper body and underbody. By identifying the pressure difference across the air dam as the dominant source of drag, a novel vent front splitter with extension plate (V.E.P. splitter) is proposed. This design eliminates the air dam to reduce pressure drag while incorporating an extension plate to enhance downforce. Consequently, the V.E.P. splitter achieves a 1.2% reduction in drag and a 125% increase in downforce relative to the baseline vehicle. Furthermore, the proposed design shifts the aerodynamic balance rearward compared with the baseline front splitter. Overall, this study presents a systematic design strategy for achieving enhanced downforce without incurring a drag penalty.</p>