So I ended up buying the genuine rotors from Holden parts, with the help of a mate in the game, so fitted up the new front rotors and Intima SR Pads this morning, no issues. Despite Holden service saying both needed to be replaced immediately, I have done a further 10000km since then, and on inspection the front pads were still roadworthy albeit low.
Went to do the rears, and the pads have even more material on them than the fronts, but was going to replace anyway, but went to put the new Intima SR pads in and they won't fit. Length wise they are about 1mm too long, and just will not fit in the caliper at all. They are the same shape in all respects as the genuine factory ones except the backing plate is ever so slightly larger.
Anyone have any ideas? Manufacturing error or defect? Maybe the factory ones had been filed down a bit?
Not sure what to do... or worst case scenario, what brand of rear pads to buy as replacement?