This is a factory original from my 2023 Tesla MS Plaid. It is 1 year old and in new condition. See the attached screen shot from the Tesla official store where it sells for $700. It fits all 2021+ model S. All you need to do is attach it to your rear deck with double sided tape like the factory does.
(this is the description of the factory original rear spoiler)
The original rear spoiler on a 2023 Tesla Model S Plaid is made from real carbon fiber. Tesla offers a carbon fiber spoiler for Model S vehicles produced in 2021 and later, including the Plaid variant. This spoiler is constructed from lightweight, cross-woven carbon fiber with a matte epoxy finish, designed to improve high-speed stability by enhancing aerodynamic performance.
The OEM carbon fiber spoiler is typically included with the Model S Plaid as part of its performance package. However, in some cases, it may be an optional feature or installed post-delivery. If your vehicle did not come equipped with the spoiler, it can be purchased separately through Tesla's official shop or authorized resellers.