I never saw an Aurora in any of the shops I was associated with between 2005 and 2019. I'm not sure when I last saw one moving under its own power. Cadillac Northstars are well known for their failings. Did the Aurora V8s installed in the Shelby Series 1 cars also have oil circulation, head gasket, and carbon build-up issues?
Cobras are valuable because they have impressive competition history and they combined classic sports car styling and handling with dependable Detroit V8s. The Series 1 has no competition history that I know of, has styling that is hard to get excited about, and whatever amazing road-holding it possesses might just hasten the demise of its frangible engine. Six figure valuations have more to do with modern monetary policy than they do with any lasting appeal of the car. I remember seeing a few of them at Symbolic in La Jolla almost twenty years ago. They're not entirely unattractive, but the GM components and switchgear combined with too much silver make them quite resistible in my opinion.