> I see curiosity and imagination as two sides of the same personality trait expressed in different ways.
That's because the world of today is both complex and complicated. Imagination is needed to decipher things and curiosity to get you the urge to find out more. I would argue that it's two different traits both selected by evolution. Let's imagine a tribe on savannah where some are smart enough to imagine lions hiding behind a hill and not sufficiently curious to find out by just going there, it's great to imagine throwing rocks to scare potential predators away. So you need both, they're complementary and might not even have to be expressed in the same individual but beneficial if they do.
They don't wonder how a car works because they can't even begin to deduce how it might work, from the observable outside in, because they lack the imagination to make those deductions. Someone who's curious might see a car and think, "How does this work? I can see the wheels spin and propel it forward, but something must be making those wheels turn. How do they all spin at the same time? What turns the push of the pedal into making the wheels turn?" etc.
I see curiosity and imagination as two sides of the same personality trait expressed in different ways.