I have a Laguna 2.2DCi estate, 54 Reg. Same thing, sometimes it thinks I am a submarine in the Irish channel, its all over the place. I tried to trace the aerial, as far as I can see, the cable is sealed into the housing, can't tell if there is a cable break? I will try at the Sat Nav end, if not, will try to order a new aerial like Ian Britten said.
Stu
October 2009