Looks the same as mine:
Thanks for the photo, looking at that little metal latch, it looks like it's securing the seat better, while the latch on mine doesn't quite go all the way down.
The rear seat doesn't feel like it's secured down.
I don't think it does secure down as such - as I recall, the squab just drops into place, and lifts up as needed.
This is true, but it shouldn't be able to move freely when you sit down on it, i.e. you shouldn't be able to sit down and be able to lift up the seat (at least I don't think so). I can't say I've ever sat in the back of my own car to ever notice!
Is it possible that the extra padding may have raised the latch enough to alter the angle of dangle. All it needs is a fraction of a mm or two to affect the snap action.
This is what was originally the problem, so I removed all of the sound deadening from around the latch, and removed a load from where the seat bottom touches the carpet, and this greatly improved it. But it's still not how it should be.
I will investigate it more when I have the time, but I think it should probably be ok for the MOT.