 DioGuardi said that Spears "worked really hard" and called her "unstoppable".In September 2006, Rotem told MTV News that he and Spears were trying to innovate the current sound of radio at the moment, exemplifying Nelly Furtado's "Promiscuous".On November 8, 2006, the day after she filed for divorce from Federline, Spears recorded "Radar" with Ezekiel Lewis and Patrick M. Smith of The Clutch at Sony Music Studios in New York City.