I'd sort of decided that mine didn't use a bracket only the 2WD variable shelf one where the plane has to fit in is bolted and the need to dig around looking for the holes. The parts list hasn't got those bolts for the 4Drive but in for 2WD.I have a 2017 2.0 TDI 190 4Drive. It came with just a thin piece of carpet and a round piece of foam in the boot when I bought it.
I ordered a spare wheel kit from the same place as you, Caffyns, for £340. The part number for the kit I ordered is ZGBBOM235SE.
It will arrive in a few separate boxes. You get a space saver wheel, jack/tools, foam surrounds and a new boot floor. There is absolutely no modifications required to fit it, just goes straight in and fits perfectly.
You lose a bit of boot height, but I prefer this as you have a flatter load area with the rear seats down.
Mine has already saved my bacon when I recently got a puncture.
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Reluctant to take my factory fitted boot apart to check, quite a bit to move out . Saying this there seem to be variations in the parts supplied between the model year and whether Cupra. Thus the need to supply the VIN to the people when ordering.
The flat plane is as you say is handy. No lifting up and down over a big lip, but then the 4Drive axle takes up space so in reality you don't loose that much space, just the width of the skinny and a bit.