FYI to shitwizard. The Sunnyvale trailer park created for seasons 5-7 has been removed from the site it was on. Open field pretty much now. Some one posted pics, or a link to recent pics, I forget which.
I can't speak for Clattenburg, so my own opinion is that the 7 year show had reached it's zenith, as a cable TV series. Stopping it when they did ensured it wasn't going to get old, and dulled by regurgitating familiar 'schtick' past the freshness date[so to speak].
More movie(s) I think can, and should happen, which could easily spur a TV special using sets, and props developed for said 3rd movie.
Now that a much greater US audience is present, the idea is easily worth the effort, as long as Clatty is at the helm. He's the true 'Capn' of the shitliner', and I can't imagine it without him producing/directing.
Worst case ontario? Waiting too long, and either prime actors aren't able, or the majority of fans have just moved on, and interest wanes.