I think I'd end up resorting to violence if they tried that sort of stunt on me (unless I was clearly in the wrong), what a bunch of tossers.
Which carpark is it? I've ony been to haworth a few times and I've always parked in the big carpark that has different levels and comes out at the top near the church. Is that the one?
edit - looks like I always park in the weavers hill carpark