A Pacifica owner in Pennsylvania made a bizarre discovery under the seat of his long-unused vehicle: strange white formations resembling fluffy crystals or fungal growths—eerily similar to what you’d see in The Last of Us.

When he lifted the floor panel in the trunk, he found even more of the mysterious substance, which continued to grow despite repeated cleaning attempts using household products like Mr. Clean foam, hydrogen peroxide, and specialized carpet cleaners.

The owner suspects the culprit might be a spill from six months ago—Listerine mouthwash—which may have seeped into hard-to-reach areas. Adding to the mystery, he lives in a region known for cold winters and salted roads, which could be contributing factors.

Online reactions were divided. Some users insisted the growths weren’t mold or fungus, but salt crystals formed from a reaction between road salt, metal, and leftover mouthwash. Others argued that Listerine wouldn’t trigger such a reaction.

Biologists and crystal experts weighed in, noting the structure resembled salt deposits—similar to those found on the walls of old buildings or bunkers. Most likely, the formations are the result of corrosion on the car’s metal components combined with road salt and moisture, creating pale, crystal-like growths. The mouthwash and cleaning agents may have accelerated the process by creating a favorable environment for salt buildup.

It’s unlikely to be mold, which typically appears softer and lacks the rigid, spiky texture seen here. The appearance of such growths suggests the need for thorough drying of hidden cavities in the vehicle and the use of anti-corrosion treatments.

Despite regular cleaning with strong chemicals and physical scrubbing, the owner has yet to eliminate the growths.

Source: trendymen.ru/reddit