Update: Got the car back having helicoiled plug no.2 and replaced all 4 denso iridium sparks with stock-spec NGKs. Car seems to be better off for it, idle is quieter and it pulls better.Update 19.06.2017
Drove the car to the West coast this weekend, car went link a train and rode great on the new suspension settings.
But...when I got half a mile from my destination I hit a pot hole and my spark plug jumped out of no.2 pulling the aluminium threads from the head. (literally the furthest point away from my house). Got it towed home with a massive hangover on Sunday morning.
Getting it helicoiled tomorrow but its frustrating to say the least. I hope the threads can be blown out of the cylinder.