Toyota is working on a new "hitchless towing" feature, where you'd be able to tow another car behind you without actually being connected to it physically. You'd just be connected wirelessly. They say a lot of the necessary features are already available in their Sienna minivans. So they've been testing it out. (Here's a video.)
The trail car behind you does everything you do in real time. So if you change lanes or hit the brakes, it does too.
So far, they've only done slow-speed tests with a safety driver in the trail car. And they're leaving a big gap between them, just to be safe. But they're hoping to shorten that gap soon, so the two cars are almost bumper-to-bumper.
Eventually, you could tow a camper with any car, even a Prius. It would also be handy if you had to follow a friend somewhere and not lose them. But for now, they're only planning to do it with unoccupied vehicles in the back. They could start testing it on highways by next year.