In the public sex scene, all the non-actors' reactions to the scene were real.
In the restaurant scene, when Jason Statham was explaining to Amy Smart what he did, her hiccups were genuine.
When the Google Earth satellite views zoom-in they show the real locations where the scenes were actually shot.
Jason Statham initially had reservations about accepting the role of Chev Chelios mainly due to him not believing himself to be particularly funny. In response to this, directors Brian Taylor and Mark Neveldine told him to simply play it straight and let the dialogue be funny.