I read on the SR modding forum that the GoG release does not support mods. Tried installing 'Things To Do In Dominatrix' and it locks up during the wall of text. Any chance someone could shed lights on this? or if it's something that will come in the near future?

I guess its trial & error. Got myself some small mods (like no pixelation & re-introduced cruise control) and that works.

edit: Ok, I read a bit into it. Its apparently a supermod in the scale of the Gentlemen mods of SR2&3. SR4 modding lean more into steam workshop stuff so I guess it might depend on files from the steam version since it was never thought of by the modders to do it without (an probably not possible to mod some stuff without) steam.

You might ask for help in places like this but do not expect them to have a workaround; my impression is that they are shellshocked by a legit non-steam version of the SR series.

edit again: after skipping above linked thread to the last page they already waved the white flag towards the gog version :/

That kind of sucks. Really enjoyed the replayability that the Gentlement mods added. Not inclined on picking up a Steam copy; even during a sale, since I only wanted to play these in LAN anyway but having mods would have been awesome.