I Have alwayes used Pledge in the spray can to clean and protect the plastic on my vehicles. It is advertised as a non petroleum product and seems to leave enough of a film to make the bug removal process a little easier. lately to save money I have tried walmarts generic furniture polish and have not noticed much difference.
This has worked on the windshield of my Super 8 and I have used it for the face shield on my helmets for over a year. I live in florida so I have never washed my bikes, just used a soft clothe and this product to clean everything. Both Bikes look like new