Wouldn't that only run in one direction ? what about when you want to put the windows back up again ? I'm not sure about this one to be honest.
I'm in the middle of doing this job at the moment and have the regulators and motors out. I'm wondering if it's definitely the case that the e28 motors are faster, because I have a set I could fit. But given that the old dried up grease is like glue, I'm expecting a big improvement already that will probably be good enough for me. The reason I ask is, everybody seems to have replaced the motors at the same time as re-greasing everything, so how do they know it's the motors that are faster, the e28 ones didn't seem any faster when I ran them straight off the battery. I have the newer motors.
And someone in the UK might find this useful - window felt channels I've just fitted, £11 for all four windows. A lot cheaper than the Walloth Nesch price. They fit very well, but I'll confirm when the job is done and windows move.
https://www.woolies-trim.co.uk/product/1023/window-channel