Hi mate, this is something I did just last week! They can be fitted, all of the holes are there, you'll need the trim pieces from the cupra to.
The hardest part is removing the fixed windows, I tried cutting the sealant off but it took ages so ...... I smashed the window and it made it much easier! make sure you get off most of the sealant tho otherwise the seals won't sit right.
One thing that I didn't get with the windows and seals were some nuts that fit in holes so that you can screw the hinges in, but you can order these from seat for 35p each, and you'll need 14.
If you need anymore info just ask! Kyle