DriveClub has sold at least 2 million copies, according to a post by game director Paul Rustchynsky.
We asked if this included PS Plus Edition sales or not and were told by Rustchynsky that "this figure was reached prior to the release of the PS+ Edition". So this means that the 2 million sold figure is for both retail and digital sales alone.
Considering the poor start the game had, we're delighted to see DriveClub has sold so well. It's improved so much since launch that it is now a completely different game. It deserves all the success it gets really.
If you are yet to try DriveClub then we suggest you check it out.