The car costumes have two pieces that clamp to the windows and a small piece that attaches with a wire to the grille of your car.Marcus says it's best to keep the windows up when driving with the car costume. Many customers opt to use their back windows. In addition to spreading holiday cheer, the decorations serve a practical purpose, too. "They're a great way to find your car in a busy shopping mall parking lot, because the antlers stick up above the top of the car," says Marcus. (See: " Car safety tips for the holiday shopping season.") Car costumes aren't the only way you can express your holiday spirit while driving. You can find antenna toppers with snowmen and Santas for about $10 and snowmen magnets for $8 that you can put on the side of your car. Decorative stickers that peel off easily once the holidays are past are available for $15 from various retailers. For the traditionalist, a wreath can be wired onto your front bumper. For those who love Christmas lights, you can buy LED rope lights to wrap around your car while it's parked in your driveway. No matter the season, flirty car owners may want to purchase "car eyelashes" for their headlights, available for less than $2 from Amazon.