Mine also leaked where the glass attaches to the plastic frame so I sealed that also with stuff from Napa. My plastic frame was cracked so I glued it with super glue and then used the butyl tape and no leaks.

 

Silicone is not advised for this problem. Acetic acid released during cure will initiate and accelerate corrosion.

I used white silicone-free DAP sealant on a cheap used 01 truck, applied to the trim from the outside, without removal of anything. Cost, 3 bucks, time, less than 5 minutes. Perhaps not permanent, but whaddya want for a $500 truck? It doesn't leak now, and it matches the color.

 

The plastic trim is not connected to the window. I also caulked the crack of a truck several years ago. Helped quite a bit.. couple years later i removed the window and resealed it to the cab steel wall. That is where the butyl strip seals... the trim on the outside is just window dressing, does nothing.... but filling the crack might keep out 90% of the leaks.

 

Think like a water drop...that plastic, when sealed to the cab prevents most rain water from contacting the failed factory glass seal. Window dressing repurposed, sans silicone. My leak seemed to come from the top edge of the glass, and although rain can still contact the sliding window, it no longer rains inside on the top off the back seat back.

 

My '97 leaked like a convertible with the top down if you were sitting in the back seat on the passenger side (super cab). I fixed it by using clear silicone caulk all along the top seal.

 

It may not be a problem now, but wait until it gets mold, or mildew in your upholstery from the moisture.

 

Hopefully you don't end up with any mold. or mildew in your upholstery from the moisture.