booked my z in today for mot, sure it would pass mot till i got there tryed the washers out, and they failed just bits of water hitting the bonnet, poked a pin down the holes got the drivers side working but not near side, pulled the cover of the bonnet and both 1 way valves were blowing water out of the pressure holes, meaning they had both failed, had a word with the mot guy told him one jet was hitting the screen both sides he said if they both dont hit the screen then its a fail if it fitted it has to work, cancelled the mot took the 1 way valve of the near side and all works well booked it back in for thursday, wont be able to get the valves till after that but at least all 4 jets are hitting the screen....dont they know most of us only go out in the sun and dont need washers and before i get a lot of comments on you should have checked it before i went it was fine on sunday