check this out
http://www.pontiac-interface.de/
Problem is you must build the interface.
HOwever, I bought a cable from
http://aldlcable.com
it comes with several softwares. However I have not been able to use it at this time as none of the softwares is able to detect the cable. I have not investigated much at this time as I have no problem with the car and will look more seriously into that issue later...I would like to hear of anyone using this with success....