IMO it depends on where and why they are leaking... simply replacing with new seals would not fix my issue... I had to do something similar to what shipkiller posted in #8, but I pulled all of my seal rails off, cleaned everything off, then resealed it all, using a combination of the rolled window sealer and black auto RTV. Now it will only leak a little if I spray water sideways at the windows... but rain and careful where you are spraying car washes, I have no more leakage.