The most common features in modern cars that help to reduce air friction is the streamlined design of the bumpers and spoilers. The streamlined shape of fast cars also helps to reduce drag.
Cars with good aerodynamics.
Their shape and aerodynamic efficiency makes them streamlined.
aircrafts and fast cars are streamlined so that the air flows over them more easily
Ferrari
Helps improve fuel mileage.
the way they were desinged by the builders
race cars are streamlined so that they can try to be as quick as possible and also so that they can acheive the highest speeds that they can. i mean they are streamlined because they want to be quick and overall they wont to win the race :)
to be able to get through water as easily as possible, the same way that planes and fast cars have to be streamlined.
less wind resistance, better fuel mileage
Lorrys air not streamlined beacuse there is no where for the air to go when it hits the truck. But some lorries are streamlined but not to the exstent of cars like the renault k-80 which has curves to direct the airflow
To reduce air friction.