You didn't even ask yourself or them if the DRM Modding Team has purchased rights to reproduce those cars (which weren't road legal anyway) ? IF there's some grey area, back in the 80's and early 90's, a lot of racing games included real cars without asking manufacturers permission and never heard any of them been taken down.Well, to be completely fair, you're using the likeness of a manufacturer's cars to generate income. Not sure what you expect in terms of legal support.
Present released games bring official licenses to attract buyers and sadly, this is not a guarantee of quality; I'm looking at you , EA.
Btw it's the same company that secured an exclusive long time deal with Porsche years ago, selling low quality products compared to others (but still making a lot of $ because of the Porsche's aura) and took that brand away for years from simracers before we could finally enjoy some cars that made history in our favourite sim. There's a lot more to say about their sport games.
Anyway, the DRM team has put a certain amount of time and efforts to bring you quality mods and all work merits salary. If you take that work and claim it's yours, that's stealing. Same if you make money on their back.