10 Speed Sequential Gearbox with Park and Reverse - LEGO Technic, Mindstorms, Model Team and Scale Modeling - Eurobricks Forums
LEGO Technic App-Controlled Transformation Vehicle 42140, Remote Control Car Toy, 2in1 Set, Off Road RC Flip Toys, Presents for Kids, Boys & Girls - Walmart.com
Lego Technic video about Lego 2 Speed Automatic gearbox - worm gear prototype. Includes build instructions.