Not sure about 2015+ ..... To clarify, all I am saying is that I bought a TRimicro 7L0 860 251 (by Gebra 27 R 030017) and it fit perfectly in my 2014 Cayenne after I took it out of the red container (which fit the triangle like a glove). Here's a pix of the slot (empty); there is room for 2 triangles, and a pix of the code from the container.



Hatch Compartment



Trimicro

 

Is there one that fits in there while still in the red case?

 

And for anyone that's curious, if you need to remove the bottom of the rear tailgate inner panel, there's a screw hidden under the right-hand light/switch panel. You need to pop out those first and then you'll see a Torx head screw holding the panel the tailgate. Do not attempt to remove the panel without first removing that hidden screw.

The left-hand one has exposed screws that are accessible without removing anything.

Then it's just a matter of using steady pressure to pull loose the clips holding the panel in place.

 

I can confirm that a 1Y0 093 055 triangle fits in the tailgate hatch in my 2017 GTS. While still in the orange storage case. You push it into one side, under a retaining clip and then the same on the other side. First separating the velcro retaining straps, of course. Once installed you close the velcro straps again and shut the hatch. It will snap shut cleanly with the triangle stowed.

I don't have any handy but I'm going to see about stowing a flare or two in there also. Do the manuals for other countries indicate what else would go in there with the emergency triangle? Or is the hatch just generously-sized to accommodate stowing two triangles?