Either nothing will happen, or the car will fly really far, sometimes into the ocean.
Unlike previous games in the series were they were either inspired by movies or real life events, this game has a completely original story with minor things being inspired by movies.
Originally, the two episodes were exclusive to the Xbox 360 until they were released on PC and PlayStation 3 in April 2010. GTA IV saw two episodic expansion packs, the first one being called The Lost and Damned, which came out on 17 February, 2009, and the second being The Ballad of Gay Tony, which came out on 29 October, 2009, and both were bundled in a standalone game titled Grand Theft Auto: Episodes from Liberty City. The game is the eleventh title in the series and is notable for being the first "HD Universe" game, that is, the game where GTA started to become more realistic. Grand Theft Auto IV is an action-adventure video game developed by Rockstar North and published by Rockstar Games.