Hi Gummifledge is used on rubber seals ,helps with creaky soft tops, protects and stops them from cracking. Not cheap stuff but works great..
I have taken the door card off, motor off and greased the splines, I have got my hand behind and greased everything that had a channel ,also the cogs albeit the best i could..Still there ,i am going to have to work out how to remove the regulator on a cabriolet as it is different from a framed door ..looks like a bit of googling as i dont think i will solve this without taking regulator out to properly grease up the channels