It if was my XJ I'd call around to your local automotive glass shops and tell then what type of leak you have. You know, describe where you see the water running then ask them if they can 'fix" it and what type of warranty will they give.
I think the best solution will be to pull out the window, remove all the old sealant and then reinstall. Also if you have an older XJ with chips and scratches on the window it may be smart money to install a new window.
You and I guessing where the leak is happening may cause us to pull our hair out. I think to remove your old window and install it with new sealant will be $100 or less.
I asked my dealer mechanic about going from a window with the snap on chrome to the new style with the gasket. He told me my stock style is structural while the new style just floats and provides no structural load path.
I do alot of work on my jeep to include changing all the door weather stripping for the glass but for a front window leak I'd take it to a glass shop, pay them and request a 'warranty" incase that did not fix the problem.