Having had a new windscreen fitted in my 2022 fiesta st line mild hybrid vignale is it critical to have the arrow on the screen matching arrow on car body? and how would I know if it's been calibrated ?

who changed the windscreen? And which arrow are you referring to

My dealer got premier windscreens in they tell me because I had a leak but then only one half of screen would defrost so they replaced that one but I still have a leak unfortunately then I noticed the arrows on screen at bottom both sides 

The arrow is not essential to be lined up they are just centre marks if your pulled plastic panel hard enough it would probably slide in the track to line up. I work for a big windscreen firm but don't know what premier windscreen process is. All fords are dynamic calibration so they would of HAD to of driver it to calibrate it. Did your mileage change at all? can't think of any other way to prove it's been done

Thanks Gary PL no didn't check milage only recently found it needed doing after a screen change ,but you put my mind at rest regarding the screen arrows thank you. Chris