That may help a little but has very little abrasives in it and so may not help with the dull paint so much. You best choice if doing it by hand is Meguiar's Ultimate Compound, then get a good layer of wax on there, the wax depends on how much you want to spend, a few good one's are Meg's Tech Paste Wax, Collinite, or any of the Dodo range.
Hope that helps,
Chris