The washer pump failed on my +8 last year... I explained to the garage that I'd never actually used it as the car is only used in nice weather. 'Aha! Well that's the problem' was the reply. The pump sits primed (full of water) for years on end and there's never any flow - and that's what caused mine to fail. I had a look at the failed pump and it was full of black gunk.
Not an expensive item from memory - but a reminder to give the screen an occasional squirt maybe.
