As previously mentioned, a radar heading is the magnetic heading and not the track. It is amazing, however, that different aircraft/pilots can interpret this differently as on occasions it is necessary to apply a slight divergence to a radar heading to enable two aircraft to fly parallel tracks, even aircraft at the same level and presumably affected by the same wind.
Perhaps one day we will be allowed to allowed to use magnetic tracks rather than headings but no doubt ICAO will take years before making a decision.