Easy ways for a better appearance & performance accent

There are many ways on changing the appearance of a car with performance in mind. Some consider modifying their car in a way to broadcast their performance intentions to the world and possibly even outer space. Wings extending three feet off the trunk, racks of lights, and more body kit than there is actual car underneath is apparently the way to go for space alien performance. Others value subtlety and actual performance gains—even if small. Sometimes the most effective path to take is a simple blend of subtlety and effectiveness.

Subtle Distinction
Aerodynamics in custom car modification is an area where it's easy to do more harm then good. Pushing a car through the air requires a great deal of energy. Any obstacle in the way of airflow creates drag. So that three foot tall wing may look sporty, but in reality likely slows the car down. Smaller aerodynamic devices can add a bit of style without causing more harm than good. While genuine performance gains are difficult to measure without something like a car-size wind tunnel, even a minute change in airflow over a car or wing can make a dramatic difference in performance.

The Gurney Flap
An aerodynamic case in point was a length of aluminum that became known as the Gurney Flap. The story of the flap's creation follows a challenge by driver Bobby Unser to his then boss Dan Gurney to come up with something to make their 1971 USAC racecar turn faster lap times. Gurney suggested riveting a short right-angle flap lengthwise along the top trailing edge of the car's rear wing. The increase of rear downforce on the racecar was so dramatic that the team had to add downforce to the front of the car. More traction with a minimum increase in drag was the result. The Gurney Flap became the team's secret weapon to win races and was later proven to be effective in a McDonnell Douglas wind tunnel.

Easy Application
Riveting an inch or so tall piece of right-angle aluminum onto a car might do the same job, but the holes left pop rivets drilled into the trunk deck will not seem like such a great idea when it comes time to sell the car. Fortunately installing aerodynamic bits in less than an hour is as easy as opening up a browser and firing up eBay Motors, or similar. In this case the spoiler came with adhesive strips already in place, and was even paint-matched ahead of time for a seamless and factory looking install. While winning races and making history may not be the end result of an hour in the driveway, a spoiler can certainly add a sharp performance accent with minimum impact.

Guides

Park the car in the shade and allow paint to cool. Clean the mounting surface with some automotive paint grease remover or a small amount of naptha to remove wax and grease. Test any solvent first in an inconspicuous area. Never apply any solvent to hot automotive painted surfaces.

Find the center of the trunk with measuring tape. Apply some masking tape and mark the center with a pencil or marker. Measure and mark the center of the spoiler using the same method. In this way there won't be one side of the trunk that ends up with more spoiler than the other.

Flip over the spoiler and cut just the outside covering of the adhesive strips. Peel back the strips just far enough so that they can extend from underneath the spoiler. This will allow for mounting of the pressure sensitive adhesive on the center, but still allow for positioning as the spoiler is installed.

Turn the spoiler back over and carefully place it on the trunk so that the marked centerlines match up. The adhesive is pressure sensitive. Don't apply downward pressure until everything is lined up. Make sure the adhesive strips extend far enough to be pulled from under the spoiler.

Test the centering of the spoiler to make sure the ends will line up. Press down on the center line. Use more masking tape to mark the edge of the trunk line and to act as a guide. Pull the adhesive coverings out from under the spoiler while lining it up with the edge of the trunk lid. Work one side of adhesive strip at a time from the center of the trunk out.

Once everything is lined up and looking good remove the masking tape used for marking. Use a clean cloth to apply downward pressure along the length of the spoiler taking care not to scratch the paint. Pressure will help the adhesive take hold of the trunk lid and prevent any flying aero bits.