I'm just working on this now. Applying silicone to the alpine window hasn't stopped it. Perhaps I should have waited for the next torrential downpour (which was today) to install my Alpine speakers. I'm now drying one in front of an electric fan heater. Just read a long thread on a UK forum, as well as the links to other sites/articles, and now suspect that the rear sunroof may be the cause of my problem. Apparently the drain holes and tubing can become plugged/broken/cracked causing the leak. This would make sense as my rear sunroof hasn't worked since day 1. The reason I didn't consider this was that there has never been water coming through the headlining itself but have since read that it can make its way into the rear quarter panels via a leaking drain pipe. It can also cause the sunroof winder motor to short, rust, and seize. I've also had electrical problems since day 1.

Anyway, back on topic...I haven't gotten past trying to remove the cargo area carpet and rubber matting. Is the carpet for the whole vehicle one piece? What about the rubber matting? And can anyone offer some advice on removing the panels in the drivers side cargo area? I also have dickie seats that I'll have to pull out.

Thanks for everyone's advice thus far.