PRIVATE WAREHOUSE 
This is an accessory (or set of accessories) for toy cars.
It's the Choro-Q Deck System! That's the system that gives you mondo Choro-Q fun, competition, and ACTION! The system is comprised of two race track sets (sold separately), complete car sets (sold separately), and cool three-piece car assembly sets (sold separately), of which this item right here is one! The three-piece sets come as "Front Booster," "Rear Booster," and "Body Booster" sets, with each section being held in its own "card." Stack all three cards in the correct order, and your car is built!
This is a "Rear Booster" set, to be used with the "Front Booster" and "Body Booster" (sold separately) of your choice.