The only reason that works is because the game is programmed to output that data, I highly doubt GT5 or any console game will output that kind of data.
All the kits I have stumbled across have been about $100 just for the data converter, not to mention the gauges and other stuff.
Yes I know. But I bet once someone makes it into a production and introduces the guages to PD, SinBin, rFactor etc etc, those games might include a code that can work with the gauges out of the box