I've been tempted by these, but they almost seem as expensive as the originals!
You can pick up a set of A6 19" LeMans alloys on the bay and fit 235/35/19 tyres to them pretty cheaply. That way at least if you split one you can get hold of a replacement pretty easily.
Have been temped myself, but don't fancy lowering the car afterwads which It hink it would need on 19"'s