In reply to James Malloch:
+1 for council testing.
Had mine done at one 2 years ago., couldn't fault it really ('washer jet blocked' in amongst welding & brakes (eek!) ).
This year , I went to the garage that does cop cars, did the welding last year & they said the washer jets were blocked & the headlamp was misaligned & 'faulty' & the wiper blades needed changing. Funny that, they were fine 20 mins before the test..
They changed them without asking
still saved me a retest & they reduced their bill..reckon it's back to the council next year. And checking the headlamp alignment against a wall.
The new windscreen wipers are excellent, but they fcking well should be for £22