What is a good way to get it off ? Bought a new bottle of polish that comes in what looks like a squeeze mayonaise bottle, got too much on rag and have a big patch on primary cover on my Nightster !! I've tried a plastic scrub brush with soapy water. No Dice, I'm afraid to use another (stronger) type of cleaner for fear of making a permenant stain.
just be careful with simple green, do not leave it on to long. It will eat of the finish on some parts and it can stain chrome. It is also discolor the zinc bolts.
S100 and Simple Green are Great Cleaners but will also add, even though stated above leave it on too long or don't rinse it thouroughly will end up with Splotches that look terrible..
Lemon Pledge will also work on your windshield. I use it on my airplane windows all the time. I also use it to clean the bugs off the leading edge of the wings too.