If you suspect the leaks are around the window seals here's a simple
solution: Put masking tape (if possible use painter's blue tape) around the
window with the tape flush up against the seal. If you want to be extra
careful also put tape on the seal itself, flush against the edge of the tape
surrounding the window(s). This will leave you a very thin line between the
two. Take a NEW tube of GE clear silicone sealant and cut the applicator so
you have a fairly small hole from which the sealant can be squeezed. This
hole should allow a bead about the size of the lead in a lead pencil. Using
a "hook" type awl, such as that used by window installers, slide the tip
under the edge of the seal and pull it all the way around the window to
loosen the seal from the body BEFORE you try to apply any sealant. The
second time around it is best to have another pair of hands to do a good
job. While one person slowly pulls the hooked awl around and under the seal
the second person can squeeze in a SMALL "string" of sealant directly behind
the awl. Make sure you have a complete string of sealant all the way around
the window. If you somehow skip or miss a spot this can be a place for leaks
to resume.

As you move around the window you may notice a small amount of sealant
oozing out from under the seal. Don't worry. This is why you have the tape
around the edge. After you are through take a clean rag and carefully wipe
away any excess sealant. You will get some on the tape and that is why it's
there in the first place. After an hour or two you can remove the tape. You
should have a clean, sealant-free edge to the window seal.

Don't worry about silicone sealant on the painted part of the body under the
seal. Any window installer worth his salt will clean that area up before
reinstalling a new windshield or rear window should that be necessary down
the road. If this doesn't fix your leaks go back and check prior messages in
this thread for other potential leak possibilities. Good Luck.