You do realize that like the title suggested, you need to launch the car to the other side of the cliff. However, what you need to know is that you need to do this over and over again until you got your car to the other side (well, at least until you run out of cars to throw).
The game let you have five chances to launch the car to the other side or rather five cars to launch it to the other side given that you still have time to get it to the other side. You need to launch your car to the moving platform, which is located on the sea. Don’t expect that you can launch all the way to the other side of the cliff without it. Come on, surely you won’t think of that as that defies the laws of physics.