Dave Plowman (News)
You can easily park in the evening after 18:30; maybe not outside the theatre, but certainly in the West End. And free, on-street. And you can be quite a way from your destination by 18:30 yet still proceeding towards it inside the "Congestion" Tax zone, with a proper safety margin in case you encounter a traffic jam and because you may have to walk some little way from where you park and because you might just want to grab a sandwich and a coffee before getting to the theatre. You might even have to queue for a ticket - or perhaps get to that kiosk in Leicester Square (and I agree that parking around there can be a big problem, even in the evening).
Mad Ken originally intended that the Tax should apply until 19:00; he claims to have been persuaded otherwise by the theatre industry. Well, good for them. Earlier still would have been better - 18:00 (if not (17:00).
You are no more correct in that than you are in any of your other little erroneous asides. What you think you are achieving with them is anyone's guess.