After seeing the ELR with the Cascada rims, it occurs to me that GM seems to have this habit of going on a wheels mixup when a car is about to be discontinued.
For example, the Final 500 Oldsmobile Intrigue used the Aurora’s rims:
...whereas Final 500 Aurora got the Cadillac STS rims (the old FWD one, which was discontinued 2 years before this Aurora):
...and the Intrigue’s rims ended up on a Buick Century “Special Edition”, before it was replaced with the LaCrosse.
Corporate beancounting to the max, or maybe it just shows part of old GM’s problems, atrocious inventory management when they can just have all these parts lying around, and seemingly just continue to this day.