RE: P51 Wing flex
I fly mine with a outrunner and lipos I have never had that problem with this plane, and it really moves. I did have it on a cheapy plane awhile back.The way I fixed it was to use flat carbon-fiber rods and foam safe CAed them to the bottom of the wings, and then repainted. It stopped 80% of the flex. I don't know about the glassing. Like you said they are cheap to replace and it seems like a lot work for a $30 piece of foam. That is just my way of thinking..............CDP