Yesterday the PlayStation Blog hosted a special Q&A chat session with several Sony producers for Gran Turismo 5: Prologue. The event served as a way for fans to have all their big questions about the series answered as well as a chance for Sony to build hype for Prologue's release today. 1UP sat in, and here's what you missed. Beginning with the reiteration that the full Gran Turismo 5 will not be released until at least summer of 2009, Sony again confirmed that Prologue's North American release will feature a roster of 70 vehicles. While they could not provide any new word on when track downloads or Gran Turismo DLC in general will be available, they did hint at some likely expansion, assuring that fans will be "pleasantly surprised" at their plans for new content. Updates and patches for the game have been promised until GT5 is released. And no worries, Sony says there will almost definitely be a way to transfer cars and credits from Prologue to the full version of Gran Turismo 5. Answering on fan's question about Formula 1 vehicles, Sony said that there are several big F1 fans in the studio, so an expansion of cars in that area is very likely. One upgrade GT racers probably won't see for a while is car damage. "We've been working on damage for some time," said one of the producers involved in the chat. "When and how we introduce it is still being discussed. We just want to make sure it's done right." They also admitted that there's no official support for the G25 racing wheel, but Sony has heard that it will be supported. However, the new Logitech wheel being created with Gran Turismo in mind will have a "realtime adjustment dial" that will allow brake and torque balance to be tuned on the fly. If you're just sticking with the trust DualShock 3, Sony says rumble will be supported. Confirming that Polyphony Digital custom-builds their own tools for creating the game's graphics -- that's why you don't see a ton of other company's logos pop up for firmware use when starting a Gran Turismo game -- Sony also stated that Prologue's visuals should be significantly improved over Gran Turismo HD. Just how nice will it look? According to Sony, a headlight on a single car in GT5: Prologue uses up the same number of polygons as an entire car did in the PS2 iterations of the Gran Turismo series. Moving to the game's online functionality, Sony revealed that North American gamers will only be able to race against players from the same region. Online rankings, however, will be global. Sadly, Prologue will not ship with the option for private, password-protected games or voice chat -- seriously?! -- but Sony says those are both possible additions as the game grows. Gran Turismo 5: Prologue will be available in a disc-based form in stores starting today and on the PlayStation Network starting Thursday. Be warned, though, that the PSN download is missing one minor element from the Blu-ray version. Movies have been removed from the PSN version to minimize the size and download time. Most of the films can be downloaded seperately, but "Beyond the Apex," a 20-minute documentary on the series, will remain a Blu-ray exclusive. If all of this info somehow isn't enough to satiate your Gran Turismo desire, be sure to check out 1UP's preview for more details.