In case some of you don't get the joke, Just Ordinary Car is referring to the GTA 5 version as the "original", and the actual intro as the fan-made version. Although, the GTA 5 version looks much more badass with the explosions in the background (taking into consideration that it was possibly reenacted in GTA Online).
You can even remaster the other versions of Gran Turismo 4 especially the US version as well as the Arcade and Simulation mode to look how looks Gran Turismo 4 in GTA Online.
I like how in GT4, it's just professional racing while in GTAV, it's basically people trying to race normally while the whole place turns into a war zone.