Hi guys I have a friend with a Seat Altea 54 plate, his drivers elec window is slow in operation and on closing is occasionally getting stuck half way. There is a sound almost like a plastic ruffling noise. My question is do modern cars still have a plastic membrane over the inner door and has any one had experience of this becoming loose and getting stuck in mechanism? Or can you suggest other?

Thanks

If the Altea is like my Leon, there is no membrane.

Here's a guide to removing the panels for a Leon over on SCN. It may help, if the mechanism is similar. Note that if someone has had the panel off and replaced it bending the tabs in the window runners, it will stick.