I bet that filter is nice and black inside if you cut it in half! Petrol is filthy as fuel stations rarely clean out their underground tanks, if ever. Don't mention sucking up condensation water from said tanks, it's a sore subject
It's hard to give a definitive answer on the bundy fittings. Some come off easily, and some need a lot wiggling about and persuasion. I'm not surprised some are reluctant to come off seeing as VW exclude it from the service schedule
