So both my driver side and passenger side front window regulators have been changed using the bmw oem parts. Both my rears have never been changed and are working properly (crosses fingers), windows go up and down at normal speed.

Now the problem i have is that both front windows are still slow to go up and down. Both the plastic clips that hold the window to the regulator were changed.

I am debating if i should buy 2 motors and change them now...

Any ideas?