Frost King Vinyl Foam Tape - Closed Cell - Moderate Compression, 3/8" W, 1/4" Thick, 17' L, Grey

If it’s the slider often you’ll see water stains tracking down on the inside, look carefully at the top track the glass slides back and forth in. If the glass is clean it’s likely the 3rd brake light. If it’s the brake light you can obtain yourself some closed cell foam, it’ll seal better than the open cell foam they use from factory and I’d just like to avoid using silicone on paint as it’s unsightly, and a bit corrosive. Here is a product that will work https://a.co/d/0h0Pm5Qo We use slightly different stuff but that’s just because we have access to a lot of commercial glazing products. It’ll work, though. Keep the join at the bottom, I’ve done this fix lots and none have come back because it didn’t hold up.