The secret car button that almost no one knows about and is key to driving at night

This feature, which has been around for decades, reduces the glare from lights coming from behind, making nighttime driving safer.

Simply pressing a tab or lever causes the mirror to dim the incoming light.

In newer models, this system has become automatic thanks to electrochromic rearview mirrors.

These mirrors detect light intensity and, using sensors and a special coating, darken their surface to prevent glare.

When the distracting light disappears, the mirror automatically returns to its original state.