Im assuming the sensors on the Scout are the same as all Octys, if not this might be a Scout specific question.

A couple of times after I have washed the car using a hose a rear parking sensor has shown something close to the car even when there isnt anything, its been different sensors & this morning after the car had been standing in monsoon rain conditions overnight it did it again. Drying the sensor with tissue cleared it

Is this a common problem for the Octy or is it off to the dealer ??

Seems to be a problem as it has happened to my L&K a few times even had the dealer change one for me but it has happened again.

As you say clean it and it works.But very annoying