Usually with coatings as such that are non healing that's the result. It will get far worse. Think of painting over rust. Its going to bubble, and flake away while the rust spreads like cancer.
I reckon some road rocks gravel bounced up there and cracked the coating. I try to wipe it down once and awhile to check it's conditionPowder coating won't prevent rust if you drive in the rust belt with salty roads. You'd still need to apply some type of rust inhibitor over it, and keep on it. Even cosmoline only goes so far. If I can get another year, or two from the cosmoline job on my tacoma, I'll be happy. It sure beats fluid flim every 6 months.
Ford Rangers are still around because they spent a lot of time parked due to breakdowns.i always thot the old Dakota frames were much better made than Tacoma! ... just their mechanicals were total crap after a long period
ford Ranger must be the best, i still see them everywhere with rust coated frames nothing snapped broken that i am aware of
I eat mine unsalted with vinegarJust french fries!