Sloping rear glass and water

garsh

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#21
As a first data point, I tested the rear window after washing the car with Dawn to remove any oils & waxes. So plain glass, no hydrophobic coatings.

The water still poured right into the trunk.

I'll try testing some other substances eventually. Maybe even painter's tape. :)
 
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#24
I haven't noticed any updates about the problem of rain dropping into the trunk. Is it still an issue - does your shopping or luggage get wet when opening the trunk after (or during) rain?

P.S. I live in England, so it's of considerable interest to me (after RHD of course)!
 

PNWmisty

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#25
I haven't noticed any updates about the problem of rain dropping into the trunk. Is it still an issue - does your shopping or luggage get wet when opening the trunk after (or during) rain?

P.S. I live in England, so it's of considerable interest to me (after RHD of course)!
I'm the one who started this thread and, I have to say, I'd forgot all about it even though I live in a climate that has a huge number of wet days. It turns out that it's generally not the problem I initially feared it would be. The amount of water is very small and sometimes it doesn't even shoot in the trunk - it depends on the slope it's parked on and how the water beads and rolls (which can change depending upon when you last washed the car and other factors).

I also have the all-weather trunk liner so it doesn't matter much if a little goes in. The snowmelt from my skis brings in most of the water (even though I brush as much snow off them as I can before putting them in). If I have something that is extra sensitive to water, I just put it further into the trunk and any water that might splash in can't get to it.

The bottom line, even in a really wet climate, it's not much of a concern because the amount of water is so small and limited to the rear 6" or so of the trunk liner.
 

Magnets!

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#26
If you have a lot of standing water on the trunk lid (so coming back to the car after it has sat in the rain) it will flow down to the window upon opening and if you have enough volume some water may have the speed to spill over the seal and into the trunk. One partial solution is to sweep the water off the trunk lid with a stroke of your hand before opening. 3D Maxpider trunk mat works great to collect any water that gets in. I have to imagine that eventually Tesla will redesign the trunk seal so that it sits high enough to block water from flowing in.
 

PaulK

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#27
With all the rain we have had in N. cal this winter, I’ve found myself worrying about water pouring into the trunk when I need to open it.

But I’m pleased to say that it’s never been an issue. Maybe a few drops but nothing like I feared. I’m sure in a very heavy downpour it may be a problem like in the videos I’ve seen, but if it’s raining that hard it’s getting wet anyway.
 

BluestarE3

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#29
a) Don't open the trunk when it's raining.
b) This product is amazing, I use it to remove water after washing. It will definitely help for this problem.

Chemical Guys ACC_2010 - Professional Quick Drying Wiper Blade Squeegee

https://www.chemicalguys.com/quick-...MYg1Uai4sE1vr5CCs4HjofS7qsv9KnTRoC_EgQAvD_BwE
I carry a similar squeegee along with a rag in the rear passenger door pocket. The squeegee is to remove water on the rear window and trunk lid; the rag is to blot up any drips on the trunk carpeting.
 

PNWmisty

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#30
I carry a similar squeegee along with a rag in the rear passenger door pocket. The squeegee is to remove water on the rear window and trunk lid; the rag is to blot up any drips on the trunk carpeting.
Are you kidding? Do you actually squeegee the rear window and trunk lid before opening the trunk? I live in the rainy PNW and I've found it's not the problem I feared it was when I started this thread shortly after taking delivery.

I also recommend the all-weather trunk liner to protect the carpet from spills and abrasion:
https://shop.tesla.com/ca/en/product/vehicle-accessories/model-3-all-weather-cargo-mats.html
 

BluestarE3

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#31
Are you kidding? Do you actually squeegee the rear window and trunk lid before opening the trunk? I live in the rainy PNW and I've found it's not the problem I feared it was when I started this thread shortly after taking delivery.

I also recommend the all-weather trunk liner to protect the carpet from spills and abrasion:
https://shop.tesla.com/ca/en/product/vehicle-accessories/model-3-all-weather-cargo-mats.html
Even with a rubber mat, I'd have to mop up the rain water dumped by the open trunk lid before placing cargo in the trunk to avoid it getting wet. A quick swipe with the squeegee or your hand avoids this problem.
 

MacInfoSys

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#33
We don't get a lot of rain here in Southern Cal but this winter was pretty wet and I experienced the water draining into my trunk. Not much but enough to be an issue for me since I tend to have computer hardware at times in my trunk. The easy fix was to make sure the hardware is further back in the trunk. The amount of water that comes in is minimal and can easily be wiped dry with a small towel which I had in the trunk during the winter season. I also always have a trunk liner and I would recommend either Max or Tesla OEM. Outside of that, water gets in. not a lot to worry about and just wipe it if it does get in and make sure what ever you have in the trunk is about a foot further back in the trunk. Worse case when you put what ever you are putting in the trunk and you know it will rain, just slap a towel over it and you are good to go. open the trunk and if any water gets in it is quickly caught by the towel. Again not a lot gets in so the amount of water the towel sees is minimal and it won't stay soaking wet sitting in the trunk.
 

BluestarE3

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#34
I'm confused about where you perform this "quick swipe". Is it on the upper rear window, the middle rear window, the lower rear window or on the trunk lid?
The trunk lid is where the water runs off of at high velocity (due to the steep angle of the lid when fully opened), gets dumped on the rear window which then ski jumps past the gasket to land inside the trunk. Wipe the accumulated water off the trunk lid and you avoid creating high velocity water.

There's no problem with the water on the glass because you're not changing its angle quickly to cause any run-off to accelerate.
 
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PNWmisty

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#35
Wipe the accumulated water off the trunk lid and you avoid creating high velocity water.

There's no problem with the water on the glass because you're not changing its angle quickly to cause any run-off to accelerate.
That doesn't match my observations (as described in posts #1, #3, and #6).

Obviously, not everywhere you park is flat and there is considerably more surface area of the rear glass vs. the top of the trunk lid. I've noticed when parked with the car pointing downhill slightly, the angle of the rear glass is not steep enough to accelerate the water fast enough to jump into an open trunk. The angle at which it becomes steep enough will depend upon the surface tension of the water with the glass. When the car was new it did seem like the water would bead and roll much easier. Now that it's been washed and waxed a few times it seems less problematic but will still occur if the car is pointed slightly uphill (the uphill angle also increases the surface area and thus the volume of water that is subject to flowing rearward). Of course, the trunk lid adds to whatever water might flow down the rear glass.

I don't consider it a big problem after experiencing plenty of rainy weather over the previous year because the volume of water is small but wiping the trunk lid before opening it will not prevent the issue when parked pointing uphill slightly depending upon the surface tension of the water (how well the glass beads the water). More beading leads to higher water velocity and it is the speed of the water that determines whether it will be captured by the rain gutter or spill into the trunk.