What a saga.....
Despite my initial efforts not working i continued to persevere due to my sanity being at stake.
Cleaned the window with vinegar, then re-done the rain-x - Still squeaking.
After enrolling an assistant i try putting the wipers on with the drivers blade lifted off the screen, no squeak, jus as i start to think it is definetely the blade as my brother puts it back on the screen we both realise a slight squeak before it actually touches.
Next plan is to oil all the mechanism..... Still squeaking.
Then i remove the wiper arms thinking it is the spring on the back of the mechanism and soak that in oil - Still squeaking.
On Saturday i set out to clean my car but decided to have one last shot at it and ended up dismantling most of the mechanism after removing the seal and plastice cover that goes over the motor etc. Half way through oiling everything i realised there was quite a bit of play in the whole mechanism, when i investigated further i realised there is a bolt which holds one end on by going through the "firewall" between the engine bay and cabin, on the other end of the bolt there was no nut!!
I didn't have anything to hand that would fit so i put everything back together and hey presto the squeak is gone anyway, i removed the bolt and forced it back into place as its held by a rubber gromet and i think its enough to hold it just now. I'll pick up a nut at the weekend though.....
Now i don't have to drive along without being able to see anything anymore as i just couldn't handle the squeak! "Sorry Mr Officer, couldn't see as my window was covered in rain!"