A method and system for custom building a toy vehicle inside a store. A child makes design choices at a computer terminal inside the store that employs design software relating to a design of a toy car, the design software permitting design choices that trigger an ordering of components and an assembly of the toy car that simulates a real car assembly, the assembly commencing while the child interacts with the software and being completed within approximately a half hour of a first design choice. The assembly line located inside the store allows the child to dramatically see assembly of components and permits participating in the assembly by moving assembly objects to make design choices at component installation points. Design choices include style, model, color, front and rear ends, lights, doors, hood, height, wheels, engine, muffler, interior, spoiler, name and logo, and attachments.