On the Radio Station K-Chat, BJ Smith discusses his match against San Andreas which happened to be the setting of the next game in the series.
On the Radio Station V-Rock, radio personality Lazlow can be heard hosting the show. In GTA III, whose events take place after Vice City, he admitted he was fired from a rock radio station, referencing V-Rock.
A billboard can be seen at the airport showing GTA III protagonist Claude driving a Moonbeam in Liberty City. Claude can also be seen on one of the posters in the Ocean View Apartment.
While in a police car, on rare occasions a police radio dispatch officer will report "We have a 10-11, I repeat, we have a 10-11 in Los Santos San Andreas", with 10-11 being code for an Animal Problem.
The Fire Trucks at the Escobar International Airport have a city emblem reading LCFD, an acronym for Liberty City Fire Department.
On the Radio Station V-Rock, Lazlow will receive a call from Cousin Edd, who hosted the V-Rock with Lazlow in Vice City Stories, set 2 years prior to Vice City. A very angry Cousin Edd claims to have written the station's whole playlist and that Lazlow doesn't know anything about rock and roll. In the same phone conversation, Couzin Edd claims his namesake is taken from the Iron Maiden mascot Eddie the Head.
Eddie's can be seen in Vice City and the sign can also be seen above the first safe-house in GTA III.
Inside the InterGlobal Studios, is a replica of the Red Light District in GTA III's Liberty City.
Inside many Ammu-Nations are targets that are replicas of artworks from GTA III. These can be found in the targets.txd file, named target1 through target4.
Open up the audio folder for Vice City and play the file 'bust_17'. It's a short message from Ken Rosenberg saying Get Sgt Pulaski down here that fat chump owes me a favor. Sgt Pulaski is one of the bent cops from GTA San Andreas.
GTA San Andreas
Vice City postcards can be found being sold in certain shops across San Andreas.
In the Drive Thru Confessions graveyard, a grave bearing the name of Rockstar Developer, Steven Mulholland can be found, reading R.I.P Steven Mulholland. The grave can also be seen in Funeraria Romero in Vice City.
In Rodeo, Los Santos, there is a multimedia store which showcases both GTA III and GTA Vice City for sale in the window.
The song Check Yo Self by Ice Cube features on the radio station Radio Los Santos. This song uses a sample from The Message by Grandmaster Flash, which was played on Wildstyle in GTA Vice City.
Inside Ryder's home, there is a large poster in the living room featuring the cover art of GTA Vice City.
There is GTA Vice City box art sticked on a wall in Foster Valley.
Grand Theft Auto: Liberty City Stories
On the radio, the player can occasionally hear a new movie being advertised called "The Mainframe". There are billboards all over the city advertising the film and for some, there is a picture taken from San Andreas showing 5 pedestrians running for cover. One of these pedestrians is Barbara Schternvart, one of CJ's possible girlfriends in GTA SA.
Behind Toni's safehouse in Portland Island, there is a billboard sponsoring the new album of Madd Dogg from GTA San Andreas. It is believed that this was made using the rhymes that CJ returns to him during the main story of GTA SA.
In various areas around Liberty City, there are posters and advertisements for a film called Sonny Forelli: A True Story. Sonny Forelli was the Don of the Forelli Mafia family, and serves as the main antagonist in GTA Vice City. The poster also features the generic Mafia pedestrians from GTA San Andreas.
GTA Vice City Stories
After finishing the mission D.I.V.O.R.C.E. for Louise Cassidy Williams, the player will obtain the Trailer Trash clothes. These are a white tank top and blue jeans, which are very similar to CJ's default attire in GTA San Andreas.
In the missions Soldier, In the Air Tonight and Kill Phil, the Forellis look like the Hitmen from No Son of Mine in Grand Theft Auto: Liberty City Stories. However, it may just be reused model.
At the abandoned fairgrounds in GTA IV and its episodes, one of the rides is the Spinning Tea Cups. If the player looks at the background used for the ride they will see that it is a fighter jet flying out of Los Santos with the skyscrapers in the background. The background has a striking resemblance to a scene from the trailer for GTA V. This indicates that Rockstar gave gamers a hint at where the next game would be set.
There is a billboard for the company Fruntalot that features Carl Johnson.
In the staircases in most apartment blocks in the game, the player may spot some graffiti referring to past protagonists set in GTA III canon (Claude, Tommy, Carl (CJ), Toni, and Vic), that suggests they have passed away, though it is likely metaphorical as the GTA III canon is over so they won't be seen again. The only onscreen death of a protagonist so far is Victor Vance in GTA Vice City, and Johhny Klebitz in GTA V. The graffiti is intended to serve as "a little joke for fans of the series", as a different design approach to GTA IV meant the game's timeline could only inherit various fictional brand names and certain radio personalities; it is, however, no indication as to whether or not GTA III canon has been retired.
There are signs scattered throughout Liberty City that say "Hot Coffee Shop", which is clearly a reference to the Hot Coffee mod in GTA San Andreas.
There is a Sprunk manufacturing plant in Alderney and a vending machine at Roman's taxi depot. Sprunk was featured in GTA Vice City, GTA: San Andreas, and Manhunt. It has returned to GTA IV with a brand new look. Also notice that "Sprunk" is a mix of the words "Sprite" and "Spunk". The sign outside the factory is very similar to a sign for Pepsi-Cola that appears in the film "The Great Gatsby."
One of the TV shows is a program called "The Venturas Poker Challenge". It features a casino in Las Venturas from GTA San Andreas. When shown, the commercial doesn't have GTA IV graphics and art, but it instead features GTA San Andreas graphics, the most obvious being the building designs and taxis.
Similarly, footage of the Vinewood sign from GTA San Andreas is used for another TV ad for a band; it is recognizably San Andreas animation due to the transmission tower visible right behind it, which was also in the earlier game.
In Star Junction there is a sign for Love Fist. Love Fist was featured in GTA Vice City, and was also on a sign in GTA San Andreas and GTA Liberty City Stories.
There is a laundromat in Broker called Mr. Wong's Laundromat. This is presumably a nod to that particular location. You also park in front of it in the TLAD mission Roman's Holiday.
When Playboy X is killed, it is possible to go to his apartment and open the wardrobe to get a change of clothes that look like the clothing of Claude, the protagonist of GTA III.
On the front of the Liberty Tree is Donald Love, who disappeared in GTA III.
The Security Trucks are owned by the Gruppe Sechs security firm (also seen in GTA III and Vice City), although in GTA IV the name is rendered as "Gruppe 6". "Sechs" is the German word for Six and "Gruppe" means group. Also Gruppe Sechs sounds a lot like "Group Sex", another sexual reference from Rockstar.
In the bars are postcards featuring Vice City. Vice City is also advertised in airfare billboards near the airport.
The "Pager" ringtone on Niko's cell phone is the pager sound from GTA III.
Niko can receive an email from Chiliad8888, which calls the recipient "Pilgrim", makes many spiritually and philosophically-charged (and anti-government) comments, ends with "Feel the Truth, Live the Freedom", and links to whattheydonotwantyoutoknow.com. On this website there is a discussion topic titled, "Jump to a new level of Spirituality" posted by "Trooth". This discussion thread includes more philosophical thoughts, mentions Peyote, and provides a map of the Unique Stunt Jumps in Liberty City. "Chiliad" was also the name of a Mountain in San Andreas. These clues suggest that the author of the email and discussion topic is The Truth, a character from GTA San Andreas.
On Happiness Island, in front of the entrance to the statue, it is possible to find a street-artist's easel/display stand with several pictures. These pictures are all concept works of many previous GTA characters. The easel can also be seen in south-central Algonquin, very close to where Hossan's random encounter takes place and in front of the The Libertonian.
A while after the mission Diamonds Are a Girl's Best Friend, the news reports that a homeless man, Jerry Kapowitz, found the diamonds used in the exchange and planned to use the money to open a gun store in Vice City.
If the player looks closely at the chart behind Gerry on the prison, they may see the penis-shape drawing the students in GTA III had drawn.
A building near the RON Gas Station in Downtown Broker has graffiti of GTA III Era characters.
During a multiplayer race in GTA IV if the player equips a certain Female face (possibly 2) then hits a car in traffic or another player's car while pressing the talk button, the character will sometimes exclaim, "This isn't San Andreas you hippie, DRIVE!"
Vipluxuryringtones.com offers MP3 ringtones of songs from Lips 106 and Head Radio in GTA Liberty City Stories.
CDs from pre-GTA IV musicians are found in different places in GTA IV: Madd Dogg - Still Madd and OG Loc - Str8 from tha Street, both rappers appeared in GTA San Andreas. Rudy LaFontaine - Funk in Time and Sunshine Shine - Mine Until Monday can both be heard on Lips 106 on GTA Liberty City Stories, and Purser - Feel the Pain can be heard on Head Radio in LCS.
One of the in-game radio advertisements is for an online service called Babiesovernight.com. The tagline at the end and the background music are evocative of the commercial in GTA III for Petsovernight.com.
If the player looks behind the reception desk at the Hercules club, they will see a small storage rack. On the lower layer of it, a couple of clothes hangers are laying. Two of the hanged tops are tracksuits that are worn by Niko Bellic, and the third one is the orange jacket beloning to the black bucket hat pedestrian from GTA San Andreas.
Grand Theft Auto: Chinatown Wars
The player can recieve spam e-mails, from a man named Toni C. and there are two words written in Italian. This could hint, that Toni Cipriani, who was Italian, could have made it to HD Universe and sends spam.
At the beach, there are a few towels with Vice City related imagery, and even one flat out says I Heart VC. Some players have speculated that this is a clue that Vice City will be the setting of the next Grand Theft Auto game.
During the Paleto Score, the crew is talking about their first scores. Michael says that his took place right outside Carcer City, the setting for Manhunt.
If the player chooses Packie McReary as the gunman for the Paleto Score, he will describe the events of the mission Three Leaf Clover in GTA IV, including robbing the Bank of Liberty City. He also mentions Niko Bellic.
Franklin's default ringtone is a reference to the song made for Grand Theft Auto III. It plays a modified version of part of the song.
If the player picks up Packie McReary at the random encounter, loses the cops, and waits some time before dropping him off, he will mention Niko and Liberty City.
The side of the Union Depository trucks has the words Partnered with Liberty City, a reference to the armored trucks in GTA IV.
BJ Smith, a minor character in GTA Vice City, has a recreational building named in his honor.
The church at the Los Santos Cemetery is named Hill Valley Church, a reference to the setting for all of the Back To The Future movies.