Well my dealer fitted alloys the Team Dynamics 17" rims are still looking as new *touchwood* they will stay that way.
WOLF I think that you have the very same ones on too judging by your photos of CARMA. Were they on from new?
Alloys have a tendency to react to moisure in a funny way in that they yield a bubbly powdery patina to the surface, much the same as aluminium. Both are non-corrosive metals (alloys) but still reactions to moisture occur as rain is not just water but has lots of other properties in specialy the acid-volcanic rain we have nowadays doesnt help.
The secret is in the laquer that is applied to the surface of alloys to protect them, there are companies about that can re-laquer them. This is cheaper than a new set...
Just to edit this post: This info for those whos alloys are going funny and not under waranty any more.
heres a place that does what Im talking about
www.sweeneysherlock.co.uk/alloy.htm