So I just bought a super clean 56k mile Polo green LT4 coupe. Shortly after I bought it I noticed a weird pattern of some type of substance streaking down the doors on both sides! I have removed both door panels to Dynamat and fix door panel cracks. The inside where the metal door reinforcement bars are "bonded" to the fiberglass skins are what is on the back side of the area that is blistering through the paint. Is there some sort of metal piece laminated into the glass doors in this area that could be rusting? Im wondering if a previous owner has sprayed WD-40 or something on the inside of the door panel and it has permeated through the fiberglass? The car did spend some time in Hawaii so lots of rain and humidity but the original paint is in otherwise great shape just like the rest of the car. This is a real bummer!