Sounds to me like you're just too low! It's the only real explanation for it to be catching on the outside on standard size tyres, unless it was the inside of the wheel touching the spring/adjuster, but i'm unsure on the spec of Octy Spider wheels.

I 5mm spacer will only make it worse if it's the outside of the tyre. All i can suggest is raise the coilovers a few threads, maybe 5.

I may need to do that:( looks so good as it is though, im ok if i dont take roundabouts at high speeds haha
 
Dont raise it, just cut the arch liner away and bend it out the way.

Tis what I did on my cupra, wore away and cut away on the arch liner pretty quickly.