Who knew stainless steel might not be such a good idea for the exterior of an electric SUV? The entire automotive industry, that’s who.

During the Cybertruck’s unveiling in 2019, Tesla CEO Elon Musk claimed that the electric vehicle’s “ultra-hard stainless steel” body might be “literally bulletproof.” However, the Tesla truck’s exterior panels appear to be defenseless against water pistols. They apparently rust, as some owners claim.

Posting on the Cybertruck Owners Club forum, a user named Raxar risked the wrath of the Tesla faithful—already exercised by the Cybertruck’s numerous alleged design flaws—by stating that when they collected the $61,000 truck, “the advisor specifically mentioned the Cybertrucks develop orange rust marks in the rain.”

In a separate thread, the user vertigo3pc reported that “corrosion was forming on the metal” of his Cybertruck after it spent 11 days in the rain in Los Angeles.

Raxar, who also lives in California, posted what appeared to be close-up, rust-flecked images of his truck after driving it for two days in rain.

The Cybertruck does not ship with clear coat, that outermost layer of transparent paint that comes as standard on almost every new motor vehicle on the planet. Instead, each Cybertruck owner has the option to purchase a $5,000 urethane-based film to “wrap your Cybertruck in our premium satin clear paint films. Only available through Tesla.”