At first glance, the button under the Smart ForTwo’s stereo controls looks like it could be similar to the Toyota 4Runner’s Party Mode. On the button, there’s an outline of the car and some sort of sound waves blasting inside. In the Toyota, Party Mode dials up the stereo’s bass and sends audio to the rear for tailgating. Closer inspection of the Smart’s button reveals an upside-down question mark and “Off” functionality, hinting that it has nothing to do with the stereo system. The button actually prevents unwanted noises — doing the exact opposite of the 4Runner’s Party Mode — and is part of the Smart’s optional anti-theft system.
The upside-down question mark represents a tow hook while the sound waves mimic motion detection. The button deactivates the Smart’s tow-away alarm and interior motion sensor. When these security system functions are armed normally, the alarm sounds when the vehicle is raised like when it’s on the hook of a tow truck (or possibly pranksters gone Smart tipping?) as well as if motion is detected inside.
The ForTwo’s owner’s manual recommends deactivating the tow-away alarm and interior sensor during a few circumstances to prevent false alarms. These include while transporting the vehicle, when there are people or animals in the vehicle and when the side windows remain open. Entering this mode only deactivates those measures; the anti-theft system’s other monitors remain active.