My Mercedes E320 integrated sat nav activates only intermittently but when it works it is fine.

Michael, November 2008

When you say intermittently do you mean the unit 'operates', lights up and has power etc or no GPS signal. If no GPS signal then the antenna may have become dameged/worked its way loose. A dealer will no doubt empty your wallet, but maybe a mobile auto electrician may be able to help?

Mr Smith, November 2008