What happened

Shares of Tesla (TSLA 1.78%) got hit Thursday morning -- but don't freak out, it was only a fender bender. Still, the electric car stock was down 3.3% as of 11:07 a.m. ET on news that the National Highway Traffic Safety Administration (NHTSA) is investigating the company.

That's right. Again.

Two drivers examine a fender bender.

Image source: Getty Images.

So what

Now, this may sound like old news to you.

After all, it was just three days ago that The New York Times reported on an NHTSA investigation into allegations that the Autopilot driver-assistance system contributed to "at least 12 accidents in which Teslas using Autopilot drove into parked fire trucks, police cars and other emergency vehicles." Thursday's report also comes from the Times -- but this is still a different story.  

This time, the issue under investigation is that Tesla's software permits people to play video games on the vehicles' in-dash infotainment system screens while driving. Teslas have offered their occupants the ability to play certain video games on those screens for years -- but only while the vehicles were parked. Over the summer, though, the automaker apparently issued a software update that allows those games to be played while the vehicle is in motion.

As the NHTSA commented, "distraction-affected crashes are a concern, particularly in vehicles equipped with an array of convenience technologies such as entertainment screens [and] the Vehicle Safety Act prohibits manufacturers from selling vehicles with design defects posing unreasonable risks to safety."

Now what

There's an implied threat in that bald statement of black-letter law, of course: If the NHTSA deems the ability to play video games while driving a "design defect," the agency might order Tesla to stop selling vehicles.

But if the inherent risk to the business here is obvious, the solution is just as obvious: Tesla needs to issue a new software update that turns off people's ability to play those games in transit. Problem solved, and Tesla's stock should get its 3.3% right back.