When I do / When I've done / When and if

A friend of yours is going on holiday. You want to know what she is going to do.
You ask: What are you going to do when ?

A friend of yours is visiting you. She has to go soon but maybe there's time for some more coffee.
You ask: Would you like some more coffee before ?

You want to sell your car. Jim is interested in buying it, but he hasn't decided yet.
You ask: Can you let me know as soon as ?

Your friends are going to New York soon. You want to know where they're going to stay.
You ask: Where are you going to stay when ?

The traffic is very bad in your town, but they are building a new road at the moment.
You say: I think things will be better when they .