Ha...there was/is only one of me posting.
I sent the links instead of pm. If you read the links it will tell you to save the cars_def files (.dtd and .xml ) to the folder that contains romraider. So since you are running windows 7 open up:
"C:\Program Files (x86)\RomRaider\"
and drag and drop them in there. Hope it helps. If it doesnt solve you problem, join romraider forum and direct you questions to dschultz.
Post back here what you find. BTW I have not tried to use the road dyno so I don't know if mine is properly set up as well.