Its remarkably low 0.27 drag coefficient places the HS among the most aerodynamic cars in its class. Engineers meticulously examined the movement of air, whether it flowed over the exterior, below the underfloor or through the air passages. Beneath the HS Hybrid, custom-molded panels deflect wind and streamline the undercarriage. In addition, the front spoiler, available rear spoiler, rear underspoiler and diffuser fins all reduce turbulence. Efficiency isn't the only area that benefited from this scrutiny. The more aerodynamic design also means less wind noise.