I do indeed have the M56 5-speed manual transmission, but it sounds to me as if there are significant differences between the shift knob assemblies in our two alike but different cars. I can guarantee that no twisting was involved in the removal of my stock shift knob or in the placement of the aftermarket knob. I must admit that I was desperate for a considerable while, having purchased a nifty new Ractive shift knob and having no idea how to get the stock one off, and I got to the point where I was asking everyone having anything to do with my car if they could help. At the end of the day, the guy working on my audio system was the one who figured most of this out, though he didn't back up his work (basically, he was pulling on stuff and twisting hard [though it ended up not helping] without the intention of paying for or fixing anything he broke in the process). I had gotten to the point where that didn't matter much, however, and I was fine with it because he had at least some experience with interior accessories. I'm not suggesting you try something like this, because there were frightening moments, but that's what it took to get my stock shift knob replaced. The shift boot was really a b**** afterward as well because in order to pull the knob's attaching assembly loose, the rubber inside was forced to rip down the side (though I think there's no alternative). Anyway, there's my story. Wish I could help you some more.

Michael L.