Meguiar's has a wash and wax for cars that is yellow in color. I thought I'd try it when we get our camper. The 3-M stuff billto1 linked to, has caught my eye though.
Try and look for those things that are good for Fiberglass.
I've used a Meguiar's marine wax on my bikes, and am happy with it for them. The most important thing, is not to get behind on the clean and shine thing with fiberglass.
Sears has the wax applicators and buffers, that I've used before, that don't do what the heavier duty buffers do, but work well on keeping and maintaining a finish.