The dark pattern is that car dealership websites, and even car manufacturer sites (looking at you Ford) will drag you through an intricate design process only to land you on a form that will say "Thank you for customizing your dream car! We've sent your request to <salesperson> at <your nearest dealership>, they will call you" and it's completely disingenuous.
They gate these processes with lots of contact/lead gen questions so that you will get absolutely rekt with text messages, emails and phonecalls which adds insult to injury.