Hi!
This is a Photo of my car with exactly the same rims in the same dimension - 8,5x18 ET 30 (LM 124) (in the front, tyres are Conti)! And I have a KW Gewindefahrwerk in the car!
You have to use 12mm wheel spacers that the wheels wouldn´t touch the suspension - there is defitely no other way exept using another suspension (Gewindefahrwerk), not build by KW!