I found a few sources hosting the (with the 3 bonus cars and the extra DVD). Before I dive in, a few questions for those who've gone this route:
Need for Speed: Carbon (2006) remains a high-demand title within the racing game community. Despite its popularity, the game is no longer available for purchase on modern digital distribution platforms (Steam, EA App, GOG). This unavailability has led to the widespread classification of the game as "abandonware" by the community.
Technically, "abandonware" is a community term for software that is no longer supported or sold by its original publisher. In the case of NFS Carbon , EA delisted the game from digital stores in 2021 due to expired licenses for music and car brands.