I can’t imagine that fitting after market would be particularly cist effective, these things are so cheap & on almost every model these days.
I’d hope they’re adding them as in its the proper vauxhall/psa part that just needs plugging in & software updating & it’ll work as per the factory but if not then that’d be a huge no from me.
That sheet business is exactly like the stunt of sign this contract whilst the rest of the contract is covered by another piece of paper, had that pulled on me at 17 to hide the awful terms they had you agreeing to