[drover]

If you change your filters like me at 10K km no real need to use it, just spin off a filter, but keep well clear as it will spew out heaps..... as for a fix, really depend how bad you mangled it, if its not turned into a hollow and there is some meat left then a large star driver, heated up then pushed into the last remnants of the phillips star, hopefully that will make a new shape but if its comes out is another problem.....

Other option would be to drill a hole into it smaller than the threaded section and then screw a small bolt into it as the bung..... need to flush the hell out of it afterwards though............ just leave it and do the big drop until the brain has a light globe moment or you find a bung.

I have rounded off the end of a filter cap on my Colorado (same housing) and devised a way to get the stuffed one off but destroyed the cap I the process.... I keep a couple of old caps for just in case, some brands you get the filter but not the cap so pays to have one in the spares box, toss the old filter though .