How to say "really"?

Question

I'm trying to find a good way to say "really?". For example, I see a nice car and I ask them it's theirs. They respond yes and I want to say something like "Wow really?"

I sometimes say "sí, verdad?" I've also heard "de veras?" Are they pretty much the same or is there another phrase that is better in this situation to use?

Answer 1

really? -> ¿de verdad?, ¿en serio?

I've also heard: ¿de veras?

I think any of these are appropriate to express surprise whether negative or positive.

Saying: "¿sí, verdad?" sounds more like a asking for confirmation, like you know something is right, but you are double checking more than questioning.

Answer 2

what about....

"Esta pinche loco"