I've read the rules a few times and must be missing something.
Step one on Virtual Dream (end of turn) is to discard all remaining Dream cards. These are the cards in the numbered slots, correct?
Step two is to slide any Z cards to the cheapest spaces and then flip face up. I can't figure out what these are or how they are generated. I thought the Z cards were the face down deck that I buy stuff with.
There is a card (Interrupted dream) that lets you flip a card in the dreamscape (one of the face up cards). It is used to prevent a card from being discarded. This way, you can save it for the next turn and it is cheaper to buy. Hope this helps.
Elvisier said it perfectly--Interrupted Dream lets you flip a card in the dreamscape to its opposite face. In the solo variant, the chief function is to prevent a card from being removed from the Dreamscape.