Originally Posted by Mandingo

If it's the yellow poo stuff I've seen, those cleaners won't work. It has reacted with the clear bra and pitted it most likely. The stain is more visible because of roughness that is catching the light. Can you feel or see any actual roughness? If you look at the stain at a shallow angle with good light you might be able to tell.

I've heard this can be removed with a blow dryer or heat gun (be careful not to cook it!) or in some cases denatured ethanol (though this seems like a bad idea). Google these approaches first. I haven't tried them myself.

Usually Novus plastic polish #2 works for me on all but the very worst poo stains.