Hi Graham, I have just been out and looked at the wiper arm on my car. I never seem to look at things like that, normally. The drivers side wiper arm does look a bit complicated, and expensive to replace, so I would either take great care, or, if you know someone expert with cars get them to do it. There are some good independent garages about. I use and have done for years a mobile mechanic to do all my servicing and any major repairs, but he does not want to go much further than Sutton Coldfield, generally. Let us know how you get on. Regards, Peter.