At this point I am convinced the guys at Criterion have just gone completely batshit insane. They've introduced motorcycles into Burnout Paradise; they're introducing movie-themed cars and a party mode, and now this. Tiny little collectible cars, based on classic burnout vehicles. There will be 9 vehicles in this range in total, with the the Carson GT Concept P12, the Kreiger Racing WTR, the Hunter Takedown 4x4 and the Hunter Manhatten represented in the screenshot.
The tiny cars will be released next year as part of Criterion's continuing efforts to work themselves to death. Not sure if they'll be drivable, but then what else would you do with them? Until they announce the "Putting Things Into Your Orifices" pack, it's probably safe to assume.
Criterion Announces Burnout Paradise Toy Cars [Criterion Blog]