agree that this is a common GW problem :evil:
I've posted my fix on this similar situation for my port side window.
I removed the panelling, trim cover, and 18 or so window clips that hold window and pulled out window.
Once you take the install trim ring/cover off, with the help of a buddy holding a bright light on the outside and you on the inside, look for light penetrating thru the edges where the seal is not 100%, this is where the water is getting in.
you will need to either reposition the window in the cut out to properly or better eliminate the small gaps, or may have to get a dremel and slightly enlarge certain areas to make the window fit better in the hole.
I used window installer's butyl tape as a sealer and "sticking agent" for the window. the stuff works great and easier than silicone and doesn't ever dry out, or crack.
good luck.