Hi guys, I've been investigating why my rear wiper wont work and turns out there's a chunk of motor missing!! lol Tried taking the wiper arm off but it's well and truly stuck! the 13mm nut took some shifting with a big ratchet, but cant for the life of me get the arm off. i tried screw drivers in behid it and gripping it with a pipe wrench butthis thing is stuck!! I'm not bothered about damaging it as it's damaged anyway but dont want to hurt the car or glass... Anyone know how to pull it off without causing damage? cheers.