Read what he said again Reuvers. You cannot really buy 4x100 to 5x112 adapters as the pcd do not go well over each other ie some of the bolt holes are too close for it to be viable. The
problem he has is with running wobble bolts, probably on a 4x100 to 5x110 spacer, which I agree I would not want to do on a car that has any half decent power. The 4x100 spacers you can buy normally are not made by big companies as they wouldnt want to put their name on them. Others come in 2 piece which are pretty much bolting a 4x100 by 5x100 to a 5x100 by 5x112 adapters which I also think is a pretty bad idea.
Could possibly look at S3 or mk4 golf hubs but dont know if they will fit or what else you might have to change aswell.