The Astra is the "car no one knows about" for reasons already listed, poor advertising (print ads alone stopped cutting it in the late 80s IMO, if not before) and Saturn's small retailer body.
Hopefully, the new Saturn ad campaign that debuts later this month, (TV, not sure about the 'net, billboards, ATM ad spaces, etc.) will give the marque a boost, although when I last read about it on SaturnFans.com, the Sky and the Astra weren't a part of the campaign.
Even though this generation Astra won't sell in the quantities my car did, from the casual observer standpoint, it already appears GM designed this car to fail in the US market by not advertising its presence here ad nauseam, like it did for the Malibu.
As for the list in Perian's OP, I'm glad to see the Aura at least has returned to a "normal" inventory status.