Found these on Vertex. Like I said, pricey. But I like 'em. Just stick on with (silicone) adhesive. Use silicon, because, if you change your mind, it'll just peel right off - leaving no gluey gunk or damage.
Porsche Boxster 996 Gauge Bezel Instrument Rings: Interiors Styling & Dash Boards Gauges
Obviously no need for the two small rings on our cars, so those are extra. Hey, still I've got them. Maybe I should post FS on a 996 forum for $$$$$$$$$?!?!