Now days it is more for decoration. long ago during races cars would have an iconic and easy to recognize color scheme which often included a stripe to let people identify which car was which. now we see races with much better position tracking and race info being displayed along with a very unique set of colors and sponsor decals that make cars unique. when old race cars still heavily influenced road car design, those stripes came to road cars for the sheer purpose of making you look like a race car driver. they serve no performance purpose as the paint is too thin to make a difference on weight or aerodynamics.

Just visual.No a driver does not need a stripe to line up a car.

intimidation, any more questions?

this is where loud auto paint jobs originated. get your opponent off the line, you won in most any drag race.

Makes the car go faster. WHO CARES!!!!!

Its call livery and the reason much the same as riders/jockeys doing horse racing and it looks flash

cause the chicks dig it!

The elevation of the paint forces the air in a favorable direction for racing.

Make you ask questions...

Decoration.

Racing stripes, also called Le Mans stripes, were applied to race cars to help identify them in the field during races, and to help a driver realign a spun out car with the track.