Reading the original post cars arent being cleaned.
Tarmac are a substantial nationally recognised company and it was they who told me to use brick acid on their windows.
There is no damage to any part of the window unit. As previously stated the whole units look like new.
Woodley - why will the windows go blind in sunlight.
Yesterday in the quarry when I cleaned the windows it was 28 degrees with the sun full on them.
The windows were properly rinsed.
Gone back today and there is no problem
Rob