You might want to call around your local plastic supply shops and grab yourself a small spray bottle of this stuff for cleaning the face.
I dono what you used before, but be carefull what you use on the plastic parts. NEVER use Windex !!!
Get the blue spray bottle, it's pretty cheap too.
It also works GREAT on the anodized aluminum surfaces, and will not discolor the finish at all.
Plastics, Automotive paint finishes, glass, metals... damn near anything that has a fragile surface finish.