Just so I have this straight: people are complaining that a company that makes real cars is somehow being unfair to digital model-makers by having an exclusive license with TurboSquid? Isn't that their choice?
Anyway, I'm not a lawyer, but any time you make a model with copyrighted logos (such as Ford and Ferrari) and sell it using the copyrighted names, then you better have a license or permission to do so. Otherwise, you're selling someone else's intellectual property and there's always the chance that the company could issue a takedown notice.
(Think about it the other way: suppose someone hired you to design a spaceship for a TV show that became popular. How would you feel if people made their own version of your spaceship, put it up for sale, and made money from something you designed? Then how would you feel if you had an exclusive deal with a website but then other people complained that you were taking away their right to sell their versions of your model?)
You can still make a look-alike car without the official logos can call it "Family Sedan" or something generic, but calling it a "Frod" could still get you in trouble with Ford since they could claim you renamed it to avoid their search.
Plus, there will be less risk for your customers when they buy a generic car since they may need an additional license to use a Ford-branded car in their project. They don't need to get sued by Ford because a model has a Ford logo on it.
My suggestion is to get permission from the company or talk to a copyright lawyer.