There are piggyback ECU's that can be used on the 2GR-FE. eManage and Haltech are a couple. Even stand-alone ECU's can be wired as a piggyback as required. It's not actually a question of why there aren't any, but more of a question of why it's not widely done and documented. Simple. The Aurion/American V6 Gen 6+ Camry is not in the right market to warrant having a group out there who have gone to the effort and release plug-and-play solutions for it. At the end of the day, it is simply just a family car, not a sports car. Also, the large amount of people who would rather get a plug-and-play solution rather than pioneering a solution is what leads to no development occurring. If you are after a plug-and-play solution, this is about the closest you will get, but there aren't any promises that it will work with the Australian Aurion: MWR Plug N Play Adapter - eManage Ultimate - 2006-09 2GR-FE 3.5L