Power window broken.

[Grubco]

I asked the dealership to check my two front windows as there was a slight buzzy noise when the window was almost fully wound down. The back windows were very quiet. I was told that it was just different mechanisms in the fronts to give a different noise.

So you were told there are different motors(?) in front to back, yeah? 'Cos it seems all the breaking window winders are rear passenger. I don't recall any fronts playing up.
I run all mine up and day each day, just once (no window racing for me thanks) to see if any difference occurs in travel time, noise, etc. All perfect, smooth and quiet so far.