It depends on the plastic. I'm not sure what that one is, and I can't seem to find my handbook of solubility parameters, so I would avoid using any strong solvent. Acetone is not all that effective for rubber cement anyway. What I like to use is denatured alcohol- it won't dissolve either material, but it interferes with the rubber-plastic surface bond. If you use a soaked paper towel and rub it around, it will tend to ball up cleanly. Big plus over any solvent, which tends to smear residues and leave that slightly tacky surface.
As an aside, same trick works well for removing adhesive residue from old insection, registration, parking, etc. stickers from the inside of your windshield.
David