The days of headlight conversions and booty kits are long gone. Most of the aero kits these days are wind tunnel tested and made with function in mind. Take the Evasive Motorsports S2000 from our February issue for example. With nothing more than a Voltex kit, they were able to shave two seconds off their lap time. This is a prime example of how aero plays in chassis tuning. Not just for downforce, air evacuation or diversion, aftermarket body panels like carbon hoods or trunks can also reduce weight and add strength to a car. Aftermarket bumpers also allow for removing of heavy reinforcement structures for weight savings and more airflow to the radiator. Race cars looking for function from body parts have sparked the styles and trends that many streetcars are now embracing. Although the gains are hard to measure, you can actually improve your car's performance without doing work to your engine. Here are some of the parts that can increase performance or just simply give your car a new killer look.