Sorry for dragging up this old thread but my 2011 mk4 has been a pain this morning with this very issue due to the cold weather, was minus 3 this morning and firstly i couldn't get the door unlocked so had to get in the passenger side then it wouldnt open from the inside, finally got it to open by locking and unlocking loads of times but then it wouldnt shut! just kept bouncing back open.
how easy is it to take the lock out and clean it all out and is WD40 the best option? want it to last so i only have to do it once
very poor design fault i think by Ford