4) Cracking jokes 
The poster behind Manny is more than just a hint at a drugs-related side mission - it’s a blatant nod toward fellow sandboxer Crackdown. We’ve also seen Crackdown’s name on a news ticker, and there are plenty more references tucked away in the final game.

5) Smile for the camera
We knew that the camera would return, and now it’s been placed on the mobile phone. But the official website hints at something quite brilliant, and even more exciting: the ability to upload and share your pics with other GTA IV players.
 
6) All gone to shitzu
Most vehicle brands will return, but we know for sure that the Stallion and the Comet are definitely in. And San Andreas’ fastest bike, the Shitzu NRG500, has been bettered - the NHG900RR is now the motorcycle of choice.

7) Spray what you see
Keep your eyes peeled for graffiti loaded with knowing winks. The red motorcycle on the left is a direct copy of the bike on the Vice City box art, while GTA III characters El Burro and 8-Ball are visible on the right.

8) Map of honor
Again with the self-references. While San Andreas contained maps of Vice City, IV has actual photos. One of the first promotional shots of Vice City can clearly be seen pinned to the wall of the bar (upper left corner).