I've had an issue with our passenger door lock. Basically it was jammed shut. I tried oiling the key, wiggling it, forcing it, and swearing at it. All had no effect. Then I happened to un-wind the window to adjust the mirror and I felt something give.
Now the door unlocks & locks with ease.
That's a bit weird ain't it

1986 1.9 Petrol DG, VT20 Auto-Sleeper ... 18" Sub Woofer in the back.