How much you charging! 
 
Mind you, it's doable, the Zed is not that big surface wise, I could prolly do it in 20mins if was just a wash, rinse and dry using snowfoam 
 
I must be getting old. 
 
Well, it's the setting up the gear for washing and the clear up after that takes a few more mins, but the wash itself.....  
 
  
I tend to use the 2 Bucket method, but cant stoop down to do the sills, bumpers and wheels.  
So I tend to sit on the deck and shuffle my way round the car.  
Then I have to ring a neighbour to come and pick me up again lol!