anda

[poli]

I have a friend who says ándate as a means of expressing surprise or disbelief. I have not heard others using it. Have you heard this term used?
By the way, the English term, go on, is used by some to express disbelief.

[AngelicaDeAlquezar]

I have never heard it like that.
In Mexico we say "ándale" or "anda" (this one much less used).

-- Me compré un coche nuevo.
-- ¡Ándale/anda! ¿De veras? (Wow, I can barely believe it! Really?)

-- ¿Eres ingeniero? ¡Ándale/anda, qué coincidencia! -> What a surprise, it's such a coincidence!

[poli]

That's proof of how international the Spanish language is.