It is designed to show you just what kind of driver you are. So for The Early Show's Study Hall report, CBS News Correspondent Tracy Smith took it for a test drive.
The driving monitor is easy to hide, but impossible to forget about. Before the engine will start, you have to log on with a special ID that tells the car who you are. From that point on, every move you make is strictly on the record.
The device monitors speed in turns and whether you brake too quickly. As long as your driving is smooth and steady, the system is silent.
But when you start accelerating, even if you kick it up just a notch, the Geiger counter makes a clicking sound. And when you hit the gas, the speed alarm goes off, which could be quite annoying if it persists.
And that's the point.
"It's not going to go away. The only way to make that tone go away is to drive safely," says Larry Selditz. He runs Road Safety, the company that markets the device.
After the ride, a computer printout shows hard turns, high-speed runs and more.
"Here's a good thing, you were wearing your seat belt," he says to Smith. "We can tell on a second by second basis."
The system has been installed in thousands of emergency vehicles. And will soon be available for the riskiest drivers of all: teens.
"They tend to be at very high risk of getting into a crash, they tend to have an invincible attitude and they tend to feel that a crash or something bad can't happen to them," says Selditz.
In fact, car crashes are the No.1 killer of teen-agers. The black box could save lives, but the electronic nagging takes some getting used to.
So what's more annoying, having the black box or having mom and dad in the seat next to you?
"More annoying? I'd say the black box," says a teen named Mallory.
Smith agrees. That beep gets old really fast, but it encouraged Smith to change her driving to shut the device up.
"I like to think that this system is like being able to sit next to your teen-ager every second they drive," says Selditz. "I think the parents won't worry as much because for the first time, they can really see what the kid's doing.
And there's more: Later versions will have GPS capability so parents can keep tabs on where the car is at all times.