Mafia: Definitive Edition Cars as Addons to GTA 5
When I first played the original 2002 Mafia game I was not only intrigued with the story and the history of crime families, but also the cars. When the remake came out this year, and they brought back those cars, they looked hot, unique and rather sophisticated due to my passion for vintage cars of the 1930's time period. It would even better if someone or a modding team had those cars created as add-on mods to GTA 5, then those players can customize their colors and keep those cars to themselves on their own copy of the game. It is understandable that it will take time to covert those cars over to GTA 5. However, I do hope that creating these mods over from Mafia: Definitive Edition to GTA 5 will be a possibility and come into furition in the future.
You can convert them. but licences doesn't allow it, if you convert and publish it you may have a Lawsuit.
But you can convert them for you
In case you need a tut here is one that may works for you. https://cgig.ru/2011/01/converting-3d-model-from-mafia-2-en/