Paint on any metal surfaces by rule of thumb is a bad idea. Auto companies do it because of style. DeLorean style is classic with stainless steel- unplated. Auto companies spend lots of money finishing their creations and the paint still fails. Skin oils/acids are hard enough on metal plated objects let alone painted objects. Most folks would do well from staying away from anything painted over metal unless you want to make a fashion statement even after time your statement is not what you intended.