I have the problem with 2003 Pontiac leaking water in penger side floor?

I have a 2003 pontiac Bonneville, that collects water in rear penger drivers side flooor. I have read this comes from leaky windshields and a cowling that gets moved.if so I would like to do the repair myself. The dealer where I lives is not very qualified and very overpriced.(small town) I also heard that this is a design flaw and there was supposed be a recall on it, but I can't find it. Also does any one know where the drain tube is for the ac.