Close to pushing the button on an S4 front Brake upgrade on the Old Bus. Tell me this, If I change up to the S4 disc size ( 345mm? ) what is the smallest wheel I can put on the car. I have RS4 19's with summer tyres which I will know will go on no issues, however, I have 16" Winter wheels and am wondering if these will fit or do I require spacers in order for the wheels to clear the bigger discs and carriers. Lastly, other than the bigger carrier is there any other parts required to finish the upgrade....other than the snazzy S4 brake retaining clips hehehe. Any advice greatly welcomed.