Both. The devs are working on the engine, but they are also making a car game out of it, as you can see. I'm quite sure that after it's done, the engine will be available for others (probably licensed or sold)
Drive is the game, Torque3D is the engine. From what I know. BeamNG made all the cars and stuff (physics/models), torque is only for the looks (graphics)
Intersting thing NFS 3 on CryEngine 3 http://habrahabr.ru/post/195676/ But, what is more intersting, in the near future they want to talk with the BeamNG team for a "physics of collisions"!
There seems to be a running trend of peoples work being recycled and ported using different engines all from Russia. NFS3 ported into cryengine, seems a little bit cheeky to me. Like all the cars being lifted from other games and brought into Beamng drive, this time they've taken a whole game! Not right, not by my standards