if i remember correctly, if you get a cloth and put some acetone on it and rub it on the plastic, it'll kinda melt the top layer of browness off to reveal some black......anyone else hear of this?...just be careful and use a small amount..may want to try this in an area that wouldnt be very noticeable first......id try that mother back to black stuff first, then this as a last resort! let us know what works!