I suppose that it depends (on what, I don't know offhand).
What time is it? Which thief stole my hubcaps? What kind of person would willlfully scratch a man's Porsche? Your car is red, isn't it? What happened to my fender?
The usual interpretation of "Which car is yours?" puts "which car" in the subject position. That gives the indirect question in 2. (Can you tell me which car is yours?)
However, this is an equative sentence (X is Y), and there is often an interpretation of such sentences which puts the last element ("yours") in the subject position. That gives the indirect question in 3.