Stainless corrosion is becoming more of a problem with Deloreans, due to their age, and depending on how they are stored. The sheet metal is 304 grade. If DMC had opted for better quality stainless ie 316, this would not be a problem with the cars.

Pitting seem here is in the 'second phase' Level one is very mild and even a hard buff with a wolf wheel can remove it, however Level 3 is so serious the pits can eat through the panel