Know a race car fan who would love to drive like the Stig from TV's BBC top gear. Let them put their skills to the test with this awesome LEGO technic (42109) app-Controlled top gear rally car. First, they can have fun building the rally car toy, and discovering all the elements that make this rally car model work. Take on challenges in the free powered by a smart hub, the app allows super-precise movement, giving endless play combinations with authentic sound effects. They will also get real-time feedback, including a speed and tilt log, and can test out their skills in the app's racing challenges section. There's inspirational content and videos to discover in the app too. The world of LEGO technic unique toy building sets LEGO technic sets to bring an advanced building challenge for kids and adults who love to learn new engineering skills.