its quite likely that the clips have gone but you never truely know until you open it all up!!
it could be a simple fix like the window has shifted due to the hot weather etc...
as for where to get a skin from mate, i got mine from the stealers (cos a mate works there

) and they cost £70 + vat..... i dont know how much they are from GSF etc although i know that they do the clip repair kit there (£30+vat).....
i know its cheaper to get the kit but ive been told its a bit of a pig of a job to do. with the skin its very easy....although like me, when taking the passenger side off i had to loosen the door lock off (8mm spline bolt) inorder to get at the wiring clip, once that was done it was easy

id take it apart and have a look first if i was you....it could be a simple fix
