This was previously teased in the trailer for their HBO special 'On The Run: Beyoncé & Jay Z' (debuting September 20th). The couple are seen speeding through the Californian desert in an old 1960s Pontiac GTO as they try to evade capture.
The first part of the short film, which was directed by Dikayl Rimmasch, has now been released in its entirety.
Read an interview with the director here.