Video screenshot by Eric Mack/CNET

The most super-charged version of Tesla's Model S electric car comes with something called "insane mode" that apparently lives up to its name, if the reactions of several unsuspecting passengers in the below video are any indication.

Drag-racing site Drag Times took a bunch of people for rides in the P85D version of the Tesla Model S, which is the high-performance, dual-motor version of the car, capable of pumping out 691 horsepower and accelerating from zero to 60 in just three seconds. Because Tesla is an electric vehicle, it seems to accelerate almost instantly rather than building up speed like a traditional car.

Pressing the insane-mode button takes the car from a stopped position to highway speeds in a few seconds -- and takes even the "tweenager" with her head buried in her smartphone completely by surprise. Watch all the way through to see her lose her grip.

No word yet on whether Tesla's promised driverless cars will also get insane mode. Note to smart cars of the future: this gag is only funny when humans pull it on other humans, so don't get any ideas.

Warning: the version of the video below includes several expletives and is probably not safe for work, but it's also much funnier than the clean version, which can be found here.