It's pretty easy if you just use a little common sense. Regardless of the source of the model, it is is a reproduction of a copywrited vehicle, then by createing and trying to see a commercial product with it, being a comercial, short film or whatever, you are then liable to pay the copyright holder for useage.

Since you would not have negotiated a contract with them for use, they could then put whatever monetary worth on it's use they like, or they could just sue you for damages which could be even higher.

It does not mater if you obtain a copyrighted mesh for free or purchased, if you are creating something commercially yourself.

Like I said, it's literally common sense, something that appears to be becomming rarer and rarer these days.

Way too many people take way too many things way too seriously.