People Are Just Realising What The Lines In Car Windows Do, And I Had No Idea

c.c.c @mi.slater via TikTok

We’ve written before at HuffPost UK about why dashboards are called dashboards (the word is actually way older than you’d think).

But once you’ve wrapped your head around that bit of trivia, you might wonder about the other mysteries of the automobile world.

For example, TikToker @mi.slater recently posted a video which read, “Does anyone wanna mansplain to me why car windows have these lines?”

In the clip, she was pointing to thin, black lines on the back window of a car. Watching it, I realised I had no idea why they were there, either.

So... what are they for? 

Commenters suggested that the lines were put in place “to prevent the windows icing up” or to help them defrost.

Car window experts at Miracle Auto Glass Centre confirmed the theory and added that these lines are actually wires.

“The defroster wires are usually a wire grid that utilises resistive heating that physically warms the glass until frost is removed by electric currents. When the glass of a windshield warms up, ice melts quickly and condensation is minimised,” they say.

Meanwhile frits, the black dots which sometimes accompany the lines, are there to disperse the temperature evenly, make the bond between the car and the window look nicer, and even provide a rough surface for the adhesive to stick to, Autoglaze says.

People were having a time in the comments

Some commenters jokily suggested that the lines were a sip wire for bugs (well, the wire part is right), while others said they were a “race course for the rain drops.”

“Basically they’re there because of so yeah,” another commenter said.

Others shared that the wires can be used for radio antennae, too. We couldn’t find anything to support that, but there are reports of people’s radio signals being affected by defroster wire voltage changes as the antennae and heater grid run close together.

You learn something new every day, right?