Such as the 15" ones shown in the picture below on my car?

there are many other wheels out there if you keep your eyes open. A guy was selling some sweet-looking 15" BBS wheels on vwvortex awhile back (looked just like the ones from VW GLIs 89-92). And of course there's the two styles of Speedlines from the CQ and 90.

Cast wheels in 15" are usually in the 17-18 lb. range. Forged, a few pounds less.