I've already seen a racing seat like this, two years ago. But it was the one in this
video. The guy is playing Richard Burn Rally. In my opinion it accurately replicates the rally car in question. It can be that bumpy. The thing is, not much games have the programming to simulate this. Which is a shame, because I would love to have one of this seats.
For fighting simulators i would say a suit with air pockets that would inflate simulating the compression due to G-Forces, air pressure and, in case the airplane is upside down, lifting from the sit. That would be awesome!