That would be a good additional step, definitely a plus. Though you are still dealing with a slashed roof by that time even if they can't get the seats too easily. I'm hoping the decals will be enough to discourage them.

The home made bolt setup is still going to slow them down, working in the s2000 seat bolt area is a dark and dingy place, you need a lot of light and a lot of room and a bit of time to get it right. It might be enough to have them move on to some other target.

I've got to say that stolen seats and such are much less of a problem in our parts as compared to bigger US cities reported on here all the time. I think this is more than enough to protect my car in my general region, it likely won't work as well in Miami and like places where entire cars disappear within minutes. I'm trying to discourage the petty thief, the professionals will get the seats everytime.