Wheels are a lot easier, even if there aren't that many options available these days in such small sizes. The factory rim options are:
- 12x4.5 ET45 4x100
- 13x4.5 ET45 4x100
My two K10s have:
- 13x4.5 ET36 4x100 steel rims
- 14x5.5 ET42 4x100 alloys
Anything you can find that's more or less the same should fit. Just make sure the center bore is 59.1mm, or if it's bigger than that, get adapter rings accordingly.