Flexible disassembly and assembly, DIY model modification, intelligent identification of accessories. There are multiple ways to play with two small cars, including a large truck and a small car. The small car can be disassembled and assembled separately, or the two cars can be combined to sense and play interactively. Children design by themselves and easily modify the car models. Use screwdrivers and accessories to modify the car into a variety of shapes, so that children can understand the structure of different models and simple mechanical principles.