cossie wheels on a mk6 is never going to be trouble free which is why I sold them from my 4x4 after driving it, as offset and width is wrong and rolling rear arches can help but stretching tyres to make fit loses you important grip and leaves the rim open to damage and spoils the look of a nice clean car, tramlines simply mean does the steering on certain roads feel like its stuck in wear grooves on the road or that the car wants to steer itself, for what its worth the 7j mondeo version has better offset and width and improoves handling