In 1992 Naewie was German indoor champion in doubles with Marc-Kevin Goellner , in 1994 he was German champion in men's singles and German team champion. In the tennis Bundesliga he played alongside Karsten Braasch and Jens Wöhrmann for Rot-Weiß Hagen .
After his tennis career, Naewie studied business administration in Germany, the United States and Spain . From 1998 he worked at Bertelsmann , where he B. helped to finance the internet search engine Lycos Europe . In 2000 he moved to Club Bertelsmann , where he was most recently Head of Corporate Development. In 2003 he became managing director of RTL Club GmbH. He then worked at Karstadt , most recently as sales manager. Since 2010 he has been a member of the executive board of CBR Holding .