hi i have a z8 2017 model and recently went to an off road centre , plent of mud and water but nothing harsh
anyway on the way home on the motorway as soon as i was reaching 59mph the Buggie started to splutter and slow until i dropped below that speed , it has only ever done it from this off road event as i used to be able to reach 70mph
this is currently with my dealer who have plugged a diagnostic machine in and it is not showing any faults , they have checked connections , wires etc and cant find anything
has anyone had anything similar to this fault ? any ideas would be welcome