Sony has outlined the features from the "free" PlayStation Plus edition of Driveclub and how it differs from the retail version.
When Driveclub releases on the PS4 in October, PlayStation Plus members have access to a "free" version of the game. They will have access to all game modes, but only limited to 11 cars and 10 tracks.
PS Plus members can upgrade to the full version of the game by paying a one off sum. The New Zealand price was not given as of yet. It's worth mentioning the full game gives you access to 50 cars and 55 tracks.
Traditionally, players can just straight up buy the retail version of Driveclub.
The video below explains more about the differences between the two version of Driveclub: