The Infernus roars along the freeway, knocking over pedestrians, hitting a right up the slope into the Vinewood Hills, cruising past the mansion owned by Grand Theft Auto V’s Michael .

The sights and sounds of Los Santos will be familiar to anyone who played Rockstar’s 2013 smash hit, but this isn’t Grand Theft Auto V : this is Grand Theft Auto IV , released almost six years ago.

Think of it as a reverse remake - Rockstar’s hard at work bringing its old classics to today’s mobiles and consoles , while a handful of coders are doing their best to bring Rockstar’s newest creation to an older platform. This is no mere stunt either with a few simple streets cobbled together: the team behind the Grand Theft Auto IV: Los Santos mod plan to recreate the entire city and release it as a playable download. And it all started with one man’s YouTube channel, and one classic car.

If you’re a fan of Grand Theft Auto IV, the chances are you’ve stumbled across one of Jonathan Gustafsson’s videos online under the name Taltigolt. His recreations of Vice City inside the game’s engine to his character add-ons including Optimus Prime have made him a YouTube star: the young Swede is even employed by video game giant Machinima, which gave him a contract after his video of an Ecto-1 Ghostbusters car tearing up Los Santos went viral.

Making mods is his full time job, in other words, but Gustafsson surpassed even his own expectations with his latest effort, a video showing what GTA V’s Los Santos might look like inside the PC version of 2008’s GTA IV. The web went mad for it: the clip racked up over 185,000 views. Then something happened. Unlike most viral videos, people just didn’t stop talking about this one.

“The original plan was to make a small section of the map make a video of it and then release it as it is,” he tells Red Bull UK. “It was never meant as a big project - it was mainly meant for one video.”

But he had planted the seeds of an idea, and demand on the highly popular GTA Forums website began to grow. People volunteered to help make Gustafsson’s vision a reality and before he knew it, the project had taken on a life of its own, with coders from Russia to Brazil all pitching in to lend a hand converting the map and vehicles, even the pedestrians.

Now, says Frank, one of the developers leading the project, they’re planning on recreating the whole of Los Santos inside the game and releasing it as a playable mod, along with as much of the surrounding countryside as the geographical limits of the smaller GTA IV world will allow - about half of 2013’s San Andreas.

The LifeInvader offices have made it to GTA IV too © GTA IV: Los Santos

Frank, a Brit who prefers to remain anonymous, is overseeing map conversion for the project, and says that this feat is technically possible because both games share the same core engine, Rage. But it’s still not a straight dump from console to PC.

“[The shared engine] helps make things a little easier but it's still not a cut-and-paste job. You could compare it to having a bunch of pictures on your phone and you want to put them on your pc, that's simple because you've got tools that automatically do it,” he explains. “But now imagine that your PC only accepts pictures that have a moustache drawn on all the faces. It's a pretty big task to go through all those pictures and draw a little moustache on mum, dad and your dog so your weird PC will accept the pictures.”

“We can automate some of the work on IV: Los Santos, but we have to step in and make many adjustments for it to function right. So the trickiest part of making this project? Not having an automatic-moustache-drawing-machine.”

Despite the facial hair issues, the team are working at a rapid rate, with frequent updates on the mod Facebook page showing just how far they’ve come. “Despite the difficulties, at the speed this is going I expect the entire city to be converted within one to two months,” predicts Gustafsson. “It is however not a guarantee.”

Surprisingly for something of such staggering scale, the mod itself is a product of chance. After the release of GTA V last Autumn, views on Gustafsson’s channel began to dip, so he asked a friend to help recreate North Yankton, a small but pivotal section of GTA V that takes place outside of the fictional state of San Andreas, using GTA IV’s wide array of modding tools.

North Yankon © GTA IV: Los Santos

However the duo soon realised that the snow covered terrain did not lend itself well to GTA IV’s Rage engine, so they switched to the city of Los Santos itself. “Thus this mod was born.”

We’ve seen how modders have given Grand Theft Auto IV’s Liberty City a new lease of life before, but nobody has attempted anything on quite this scale inside the game before. Gustafsson can’t give an exact release date that the mod will be made available for download, but the team have this goal in mind - it won’t forever remain a YouTube teaser.

“The plan is to release the mod for the public unless anything happens,” he says - and if they can get it out before an official PC version of GTA V (still yet to be announced, but surely on the cards given Rockstar’s track history), they may have a hit on their hands.

Vinewood Hills © GTA IV: Los Santos

Even if they don’t, they’ll still be happy. Gustafsson says he can’t wait for the PC edition of V - he’d rather have the real thing to mess around in than a finely sculpted mod. “I hope they soon can announce the PC version as I and everyone else in this team knows that we can't replace the amazing work Rockstar Games did with GTA V.”