All dealers seem to just add it. I too had them take it off.
Don't do it! You can guarantee it will be badly applied by someone on minimum wage. If the paintwork isn't prepared perfectly all they will do is seal in the imperfections/swirl marks. Also the interior seal doesn't smell very nice!
It’s way overpriced and a massive profit for the dealer. As said by Mark if you are interested get a professional detailer to do it.