Wouldn't essentially everything be illegal to resell if this was approved? Couldn't Ford prevent people from selling their used cars because it contains a Ford logo, electronics, and software all of which Ford owns the copyrights to?
If at some point Ford decided it was in their interest to restrict sales of used Fords then yes they could. Although it's likely that high end makers would do so first - a supercar maker might be more interested in protecting it's brand image by keeping broken down versions of it's car off the street. Ford is more likely to suffer from the anger of departing new buyers than gain from there not being 40year old Ford p…
Of course, this only works for really expensive but limited edition cars. If there is a several year waiting list just to get the chance to drop half a million on a car, the car maker can get away with almost anything--the customer is obviously willing to go through a lot of trouble! This is designed to stop people from flipping supercars.
Also, there is a very important difference between a voluntary contract and an abuse of copyright law. Now, if every car maker mandated such a contract on every car, it would be a big issue even if it was ostensibly voluntary. In a free market, some other company not mandating such a contract would emerge; however, markets rarely function perfectly. I think this is an interesting parallel to the whole safe boot nonsense: if there was more diversity in the market it wouldn't be an issue, but the market is heavily dominated by a handful of companies, so it is an issue from a purely practical standpoint.