Step 3
This is why having the placeholder symbol can be handy. Without it, this clue would be tricky to symbolize, at least succinctly. With it, all the clue says is that Mr. Null can't be in seat 2. This is such a swell clue that we'll repeat it above both grids, even though we didn't even bother to number the bottom one. As with most inconsistencies, both sides of this are a judgment call.