The winglike structure found behind some types of cars is officially called a spoiler, and its purpose is to alter the air flow in order to reduce lift/increase downforce/rear traction. Most of the ones on production cars are really only for looks.
Bernoulli's principal
The most recognized- is the 1955 Mercedes-Benz 300sl "Gullwing"
Bernoulli's principal
ALAE
angel
Look behind you and BEEP the horn.
flying fish
alar
ala
is fault of car behind the second car not yours
Walk to the back of the car and make sure nothing or no one is behind the car. Back up very slowly even after looking.
7 car behind