I've been putting some info together and developing an open source project of my own, called "Alt4", as in Alternative T4. It's early-days yet, but I have had some success communicating with Range Rover P38 ECUs.
Details are on my site:
http://www.swiftcomm.co.uk/alt4/
If anyone would like to have any input into the project, then please feel free to get in touch.
Cheers,
Chrisall.