Tyres, tyres, tyres. Regardless of all the other wonderful suspension bits you have, if you have shit tyres then there's not much you can do to compensate for that.
I run Federal 595SS's on my R32, first in 17" now in 18". I have noticed slightly less traction with the 18" tyres but they are more than fine in the wet.. it doesn't do things of its' own accord and is highly predictable.
There was one point in time when I had a pair of LingLongs on the back.. they were shocking! car would step out by itself around corners in the wet but like I mentioned previously, that was likely due to the 2-way AND shit tyres.
Might I suggest, with winter looming, you all try to get out onto the AHG skidpan when it's raining to get some proper wet weather experience. There is no need to panic when the back end steps out on you, go and learn how to react properly