The rear electric windows in my XE Monty are all F'ed up.

In the left hand side The window goes up to about half way and then the gears don't mesh properly. You have to push the window up to about 3/4 way and then it engages again.

The Right one does not move at all.

Any ideas Guys?

pull the motors out, pop the plate off the gearbox, clean all the s**t out from inside, thoroughly degrease the plastic gear inside it (check that the worm gear hasnt stripped the teeth off it), as well as the steel insert, mix up some araldite (a decent amount) , put it in the middle of the plastic gear and drop the metal one in the middle of it..... leave it to set, put everything back in the gearbox, add some fresh grease, check the worm gear on the motor is still asjusted up (tiny grubscrew at the end on the gearbox) and reinstall, that *should* solve your problems

3 wooden dowels work well too - see http://members.dodo.com.au/~algis/index4.htm .