Need help making a div with a background image responsive

I am trying to make the background image of a div responsive and everything I have tried hasn’t worked. This div holds the navigation and the website logo, but also has a background image. I am trying to achieve an effect similar to this website (http://www.gtroc.org/).

Codepen: https://codepen.io/anon/pen/Edvemy

They basically did the same thing from what i am seeing.

I’m not totally sure, but i think Its just that the part of the image being cutout is not the car itself. This is because the car only takes up half of the screen so it mostly does not get cut off (instead he black surrounding it).

Your web page with the GTR still looks good however.