I'm new to this site so HELLO!

Now here are the problems I'm having,

I drive a 2001 (Y reg) Audi A6 1.8T SE Avant (Automatic)

1) It seems to have trouble starting in when it has been raining all night. I'm guessing this might be a spark plug issue where I quick spry of WD40 may do the trick? If so where do I spray? If not, any ideas?

2) The car seems to rev when stationary. This many or may not be related but it occasionally stalls when switching from reverse to drive when turning the wheel.

3) The rear windscreen wash no longer shoots upwards but follows the wiper blade making it inefficient at cleaning the window.

Any hints and tips most appreciated

Other than that it's a dream to drive.