Since there have been teen drivers, there have been bad teen drivers. I counted myself among them, once "running over" a boulder while on a driving lesson with my mother at age 16. If only Ellen Bogage had a car with a "nanny mode," controls that allow parents to limit a vehicle's velocity when their teen is driving, alert them to their car's whereabouts and even provide seat belt warnings and radio volume controls. Now, a go-kart, designed for 5- to 9-year-olds, has some of the same rudimentary "nanny" features that my dear mother would have clamored for when I seized freedom and jumped behind the wheel on my own. The "Arrow Smart-Kart" from California-based Actev Motors is Wi-Fi enabled and, via an app, allows parents to set maximum speeds (though the go-kart only tops out 12 miles an hour), geographic boundaries and to remotely stop the vehicle in its tracks. The kart also has front-end collision avoidance technology, so children who don't use the brakes won't ram themselves into the garage door.