The latest incarnation to the most lavish driving simulation in the world is almost upon us, but the wait has been long. By the time it finally emerges in Europe in November it will hold the unwelcome record of being dogged by the most delays in the series, following on almost three and a half years from the mighty Gran Turismo 3 - the first must-have PS2 title that few have managed to better since.
Since then, we've had a couple of stop-gap releases in the shape of GT Concept and the soon-to-be-released GT4 Prologue, but it's Gran Turismo 4 we really care about. Last year's E3, though, revealed a can of worms from Yamauchi-san, with surprisingly candid admissions of latency issues with its six-player online mode causing headaches for the perfectionist team at Polyphony.
A year on, though, the Polyphony main man was beaming in the knowledge that his latest masterpiece is almost in the can, and that he can free up time to work on other projects - such as the tempting prospect that is GT on the PSP; tantalisingly revealed in video form at Sony Computer Entertainment America's pre-E3 press conference. But why was GT4 so delayed, and what's he been up to since we saw him at last year's E3?
Eurogamer: So what's changed about GT4 since we saw it last year?
Kazunori Yamauchi: I can't remember all the details [of what has changed since then], but the physics generation has improved significantly since last year, there's been the addition of the Nurburgring track, the driver physics have improved significantly as well in comparison to last year. Also the spectators have been improved since last year - last year they were flat, this year they're in 3D, and of course we cannot forget the photo addition [that allows users to take almost lifelike stills in the game and print them out postcard size via a USB printer].
Eurogamer: Is the online mode now to your satisfaction? Have you managed to correct the lag issues that you were talking about last year?
Kazunori Yamauchi: The network quality and network head to head play quality has improved significantly. Last year I was uncomfortable with the latency. This year the latency has been taken care of.
Eurogamer: Has that been the main reason for the extended development time?
Kazunori Yamauchi: Well, that isn't everything - but it is, of course, one of the factors.
Eurogamer: What are the other reasons, then?
Kazunori Yamauchi: Obviously the number one reason was the development and creation of the cars - the modelling of the cars, and of course the modelling of every track in which this has taken over one year since we first paid a visit to do the shooting, and since then to complete for GT has taken a year or maybe more - so those are also other factors which add to that delay.
One very important factor - probably the biggest - is in the past year is we have had to supply ten master gold disks across the year to the car manufacturers, so that adds a lot of weight onto the workload for the team to develop the game in parallel and do all the collaboration disks.
Eurogamer: Is this the last game on PlayStation 2 game from Polyphony - if so, can we assume your next project will be on PlayStation 3?
Kazunori Yamauchi: That's correct.
Eurogamer: Is there anything you can tell us about the PSP version?
Kazunori Yamauchi: Unfortunately there's very little we can talk to you about regarding the PSP. There is much to be discussed and decided, however one thing I'd like to convey conceptually especially, is that just because it's a handheld, I don't want it to just be GT4 on PSP shaved off and diluted. I'd rather it was the full specification on PSP - that's the concept. Other than that, there's really not much more I can say.
Gran Turismo 4 Prologue will be released on May 28th in Europe, with the full Gran Turismo 4 due out in November.