Theres no such thing as “real stainless”. Stainless steel 304 is corrosion resistant, it’s the cheapest and most common. 316 is better at corrosion resistance and is “marine grade” since it will hold up better to salt water. 316L is some of the best at resisting corrosion, it’s more expensive than 304 and is used in lab and surgical equipment. There are a lot of other types, like 309 for higher heat applications, etc.

Cybertruck is probably made from 304.

Definately not supprised that cybertrucks are having this issue. Especially with road salt in the winter. I’m sure the engineers at Tesla saw this coming too.