I seem to remember that the top mounting rubbers come new with a slight coating that should encourage them to get settled into the best position at initial assembly so that end of the suspension should not cause these noises, though maybe, just maybe, something made me apply a touch of red rubber grease to them when I replaced the front suspension on my older daughter's late 2009
Ibiza, I'd think that it will be just the ARB mounting rubbers and a touch of engine or more like gearbox rubbers causing that - hopefully, as these are easier to prove/disprove and fix than the top mounting rubbers.
Maybe try spraying something that does not attack these rubber components on them, maybe silicon spray.
Also road salt will be getting thrown up and maybe any salty deposits left are getting into round about the ARB passing through the ARB mounting rubbers areas - ie might vanish in Spring time.
Edit:- tip to test if its any of the engine-gearbox mountings - open the bonnet and grab the engine and seriously firmly try rocking it fore-aft and see if you hear the same type of noises.