I use RejeX
http://www.corrosionx.com/gifs/Rejex.jpg
Click on the bottle above to get the manufacturer's website.
I buy it at SkyGeek for $15 per 16 oz bottle.
This stuff was originally designed for military helicopter windshields.
It also works GREAT as a car wax.......
So one product really does it all!!!
I have used it for years with great results!!!!!!!! Cars, bikes, etc. All the painted surfaces, Glass and plastics get a coat!!!!!
Goes on easy and rubs off EASY!!!
However as per the label directions, it is best to keep the vehicle out of the rain for 12 hours after application for longest lasting results!