Clean Your Front Grill
Your front grill is a haven for dead bugs, flying debris, leaves and other items. Take the time to clean your grill regularly, using a nonabrasive cleaning agent to remove these items. Consider buying a car bra for those times when you want to avoid crawling critters from entering your grill area.
Keep Your Windows Clean
Dirty windows slow your car down. Clean all windows on a regular basis. Use a nonabrasive cleaner to keep the glass integrity at a higher level. Use a microfiber cloth or chamois to clean the glass. Be sure to use a circular motion when cleaning the windows.
Wash and Polish Your Car
The same principle applies to dirty paint jobs. Clean surfaces place less stress on engines. Take the time to wash your vehicle thoroughly. Apply a professional-grade polish to complete the job.
Push Your Side Mirrors In
Some vehicles come with movable side mirrors. Side mirrors are drag collectors. If you have a movable, or flexible, side mirror, turn it inwards. This is perfect for those occasions when you find yourself driving on wide-open freeways. Be sure to use this drag-lowering technique only when no other traffic is around. Never compromise your safety for drag coefficients, or anything for that matter.
Keep Your Antenna Down
Watch any antennae on a moving car and you likely will see it waving in the air. This increases drag, which makes your car engine work harder. Roll down your antennae. Listen to CDs instead of the radio!
Decreasing drag will improve your fuel efficiency and overall car performance. What more could you want?