'Wielding some kind of object', the caption says. It's obviously one of those Stoplock steering wheel locks, in fact precisely the one I had years ago.
And which indeed could be kept under your seat and used as a weapon if necessary. And, of course, entirely legitimate having it there
Although, these days I'm not sure they really serve any purpose in terms of security, and to that extent the pretence wouldn't work in terms of an offensive weapon.
In fact don't think I ever used mine on either of my two Passats, and the last car I used it on would have been my N-reg Mondeo, so I didn't use it from 2006 onwards.
And I never actually kept it under the seat unless I was using it legitmately
