Constar
 

In a Spanish movie, I heard me consta que... . I was used to mean, estoy seguro que... Is this use of contar also used in Mexico?

"Constar" is a verb used everywhere that means that someone is completely sure of something; like being a witness to something or having proof of something.

- Me consta que Juan pagó el préstamo. -> I am sure Juan pay the money. (Either I saw him do it, or have proof of it.)
- Dices que el panadero es limpio, pero no te consta. -> You say that the baker is a clean professional, but you don't have proof of that.
- Nosotros vimos el accidente. Nos consta que el coche rojo se pasó el alto. -> We saw the accident. We saw the red car jump the red light.

Thanks very much. Pasarse el alto is a new term for me. I have often heard volarse el semáforo.

This is the usual Mexican expression. ;)