The article isn't talking about a Top Speed limiter, but one that signals the driver whenever they exceed the posted limit on the road they're on. Just another step towards self-driving. If you've never driven a GM product with "Lane Keep Assist", it vibrates the seat bottom cushion on the side where you're close to the lane line and adds resistance to the steering in that direction. VERY weird the first time it activates on you... When I worked at TAC we called it Drunk Driver Assist...