EZR Hairline Crack Sealer for water leaks
 

I finally discovered why water was accumulating in the plastic trim cover at the base of the rear hatch window. There are 3 square white plastic supports that the window rests on outside the window gasket. Over time they tend to leak which is why when you open the rear hatch you can get water spilling out of that plastic tray especially near the defogger/AM radio antenna wire slots. I found a product that looks like milk but dries clear and tacky called EZR Hairline Crack Sealer on eBay for about $8.50 delivered. There is another similar product with some Captain's name in it but It works the same. I discovered the leak by removing the plastic trim and all of the clips because I was going to install and uninstall it several times.
I lined the tray with paper towels and reinstalled it using the 2 Phillips screws inside the trunk cover catch and 2 of the clips opposite. I washed the car and wiped it down then carefully opened the rear hatch partially and took the trim cover loose to see where the water was making the towels wet. I looked up from where the wet spots were and saw water on those square supports. After the car had dried a day, I took a skinny pointed paint brush and applied the EZR sealant by painting it on to the plastic squares, where they came through the sheet metal, the best I could. The leak was fixed. I also used this sealant around the targa top gaskets to discourage leakage. I had a leak on the passenger side where the front targa meets the windshield corner. I let some seep in places on the windshield side and then put a piece of Saran wrap there so it wouldn't stick together. That leak has been nearly eliminated. I would recommend using a drop cloth because you don't want to get this sealant on your paint or interior. One thing to mention is that there are 2 water drain holes for the hatch at the bottom near those rubber bumpers. It's a good idea not to point a strong stream of water from a hose along this gap because water can find its way into the plastic trim piece just the same as a leak could.

Here is a link to the product on eBay. https://www.ebay.com/sch/i.html?_fro...Desc=0&_sop=15

More info please
 

I have an '88 Supra Turbo and think this might be the source of water collecting in the bottom of the hatch back and then spilling when I open the hatch back. How were you able to get the sealant up to the plastic supports where the go through the sheet metal? And did you do any prep to clean and/or get rid of rust in that area before applying the sealant? Thanks.
- John

Me again. I realize you said you used the small paint brush, but it seems like it would be near impossible to get the sealant to the back side from where you stick your paint brush in. Did you just do it as much as you could, hoping it would wick to the backside? Or is there another trick? Thanks.

The sealant does wick into cracks just like water but when it dries it seals. The center square support is clearly visible in the photo. Just wet your brush and swab away. It's a good idea to pour some of the sealant into a smaller cup so you don't contaminate the bottle. Use a drop cloth so it doesn't get on your interior. The other 2 square supports can be seen if you look with a flashlight. Do the same thing and swab around where the metal and plastic meet. I used paper towels to check before and after for leaks or you could just leave the towels in there to catch any stray drops.