Sounds like you’re talking about a nifty new feature called Track Mode! Tesla is now selling it for 5000 bucks... does all the stuff you wanted! And it comes with 20’s, better tires and better brakes for free.
I've seen people imply that Track Mode will come for free with P+, but I haven't seen that information. All I've seen is Tesla's tweet that said Track Mode will be "available" with P+. "Available" could mean any number of things including free or available for an extra fee. Is there a link saying it's going to be free?