Found this on detailing world might be of use to some people (to stop dealer washing car even when told not to etc)! I take no credit for this whatsoever here it is :

Already have it - but thanks! Used it when the .:R36 was in this week for its interim oil change.

.... It was the first comment I got from the dealership when I collected the car too! LOL

This is my homemade one i use,im sure they think im a ****** but who cares.

 

i4Detailing do the hanging sign for £5. 

 

http://www.i4detailing.co.uk/cgi-bin/sh000001.pl?WD=sign&PN=i4d-do-not-wash-this-vehicle-hanging-sign%2ehtml#aDNWS 

I've still got the Detailing World one that I got in a group buy but are no longer made. 

 

What a clever idea!

Gonna have to get me ones of these