We have some awesome stuff we use at the shop. You just wipe it on with a clean rag and it looks awesome. Ill post the name of it next time I go up there...or maybe Turblown will see this post and reply first (he practically lives at the shop).
I just keep a super soft rag in my "trunk" on my bike and kinda wipe off the dirt and stuff every now and then, gotta keep mine looking better than Maggies. HAHA
Other than that, I do like a sponge bath style and hard shell wax.
Both Kawa and Honda dealers sell this Plastic and body cleaner/polish in a spray can. They each call it something different but it rocks.
I use it on my helmet and shield also. Use a clean SOFT lint free white rag no red shop rags too rough.
I am finding I am taking back the post that stated I like the Plexus. You have to buff it too much to get rid of the streaks. I like the Honda plastic cleaner.Old stand by. We are out I hope you can still get it from the dealer.
Don't you know when you was your bike, it brings the rain? Mr. Clean makes some pretty good stuff. It takes the hard water out and washes the dirt away pretty good. Then I use a shammy to dry it off good. http://www.mrclean.com/en_US/mrclean/home.do