I second Otis' recommendation for Wash Wax All. The stuff is about $10
for a quart that lasts through 2 complete washes, it works great and
takes off even ancient bugs. I have started using it on my car as well.

For the belly, WD40 is your friend. Smells great (whee!), takes it all
off, and has the advantage of protecting the aluminum under that paint
rather than corroding it.