Deep salt mines are incredibly dry places [ that's why they can store documents down there]. So corrosion would not be an issue- which is nice. Don't open that bottle of Evian-----Noooooooooooooooooo!
We do when they're not performing tacky stunts like this.
Chances are that if they'd stuck an early 1970s Lancia Beta down there it would have come out no worse than it went in.
So what does that say about the people who dreamt this up - or possibly what those people think about their customers if they actually knew what they were doing?