Used when describing rc cars available for sale. Almost Ready to Run (frequently abbreviated to ARR) usually means that the system is approximately 80% built. Usually what needs to be done is (a) install the radio gear, including the receiver and servos (b) build the linkage to the steering and throttle (c) sometimes install an engine or an electric motor (d) glue the tires to the rims and put the rims on the car (e) paint the body.