A couple of things in Superman II I was thinking about...

[mjr]

Ok, when Superman flies Lois to the Fortress of Solitude and forgoes his powers, how do they get back to Metropolis? I mean, he can't fly anymore, and I'm assuming that they can't just call for a taxi. And Lois left her car at home.

In the original "Superman The Movie", He walks to the Arctic.

But he gives up his powers, and the next thing you know, Lois is driving and they stop at the diner where Clark gets beat up by Rocky. I know it's really not relevant to the story, but they had to have gotten back somehow, together. Did they both walk back?

[El Pollo Guerrera]

You're right, so I looked it up.

There's a deleted scene in the "Richard Donner Cut" of Supes2 that has Lex being arrested by the Arctic Patrol. From that we can assume they had a way of contacting them to get out of the Arctic and back to civilization.