The only 1984 300zx that had the cruise control and radio controls in the steering wheel hub, in 1984 was the 300zx Turbo Aniversity Edition (called the AE edition) a relatively rare and still expensive model. similar options were not available until 1985 all models of the Z that ordered the Digital Dash option. These controls work an a special Radar beam. Nissan was 10 years ahead of it's time with this technology. No other cars had steering wheel controls using this technology, for another 10 years. You cannot use wires inside a wheel that turns. I have a rare special factory maintenance manual from Nissan that describes this component.