I'm quite confidant I have located the source of my drivers door creaking. I tried the 3 step method and lubed the seals (which was simply masking the issue and not really fixing it) then after few weeks the lube rubbed off anyway and creaking returned. My issue seems to be the weather seal on the chassis of the car itself rubbing against the plastic door trim on the door. When the doors are closed if I press or tap that seal I could replicate the same creaking sound I was getting whilst driving - This only happens on this particular drivers side seal, if I press the same area on the other passenger doors I hear nothing. I cut a few pieces of felt tape and jammed them between the weather seal and plastic door trim and took the car for a drive on my usual bumpy road and no more sound, except now i can hear the sunroof creaking - thats another mystery for another day though!. Now I don't want to stick felt on the door trim as it would look stupid and defeat the whole purpose of a weather seal, so my options are either "try" to have kia replace this under warranty or find a suitable long term lubricant. I've been reading on a lot of BMW forums that their dealerships have been using a product called Gummi Pflege or Carbaflo KSP105 (quite expensive) to quieten down seals.

