just noticed i mentioned above mine were Et45, doh, typo mistake ,should have been ET43 same as yours.
I think you need to go down a bit chap, they look great but i can see why your getting contact , i tried 15mm on mine and it was a no go.
praps 10-12 max on the back and 8-10 on the front, just a thought, car looks the dogs chap.