How to film cars

This YouTube video helped me to understand how i can achieve smooth car shots when filming my trailer. Particularly at the start of my trailer, it begins with the group travelling to the location of filming, and I as a director want to show a few shots of the group in the car- with a variety of different shot types and angles. 

The method shown in the video is "How to film cars on a budget" and is achieved through the use of a piece of string (i.e. safety string) that you can attach to the camera to prevent it from falling and breaking, a suction cup which will be attatched to the side of the car, a camera of course to film the shots with, a car to shoot & also a car to shoot from (along with a friend). By filming the shots of the cars this way, it is a relatively simple and easy way to get steady rolling car shots, at a cheap price with no major expenses involved.