The other option is the Dakota Digital set up. They have a harness that plugs directly into the computer that hooks to the gauges.
http://www.dakotadigital.com/index.c...rod/prd722.htm
Then use this module to connect to the engine computer:
http://www.dakotadigital.com/index.c...rod/prd752.htm
Obviously this method doesn't use the plug that you are picturing, but sort of accomplishes what you're trying to do as well.
Just another option for yah!