See all that data that is generated when people use the product? That could be mined, refined, and made into new products. All those computer screens in the car are suddenly new avenues to push advertisements. All those critical equipment are a avenue to sell repairs, where the producer has monopoly. And if nothing else, the computer inside the car can always be made into a platform.
Take a product, throw in some DRM, and voila, you can create revenue after sale. The DRM and the accompanying user agreement is the glue from which all that extra revenue can be made.
From a company perspective, I don't see how much of a choice they've got. A competitor can use that extra revenue to lower prices for which a consumer won't be able to assess when buying. Selling equal-looking products at higher prices normally spells doom, and regulations haven't even begun addressing the issue.