There's been a lot of talk recently of additional brands joining Chevy, Ford and Toyota accross NASCAR's big 3 promotions, and these seem the most likely... Here's the best analysis I've seen:
A: Extremely doubtful with Fiat at the helm. Maybe if the Challenger/Charger move onto the new 'Giorgio' platform.
B: GM won't spend more money to get it's other brands to compete against itself. Besides, GMC would only be in the truck series, and there's no need to advertise Buick since China keeps it afloat.
C: Likeliest out of these four. They have trouble with their motorsport programs as it is, but would be able to slot in with comparative ease (Titan, 370Z, Altima. Or, if they follow Toyota - Titan, Altima, Altima).
D: Not likely. VAG has had to downsize their motorsports programs due to dieselgate. They won't spend the needed money to race here.
What do you think? Does the sport need another entrant? I'm personally in favor of Nissan, I think their new design language is super sexy and sporty and would be a great fit in NASCAR!
Sources:
nascaronfox Instagram: https://www.instagram.com/p/BWNutJmFVW-/
WindsorShatzkin|/r/nascar: https://www.reddit.com/r/NASCAR/comments/6lo1fa/which_manufacturer_would_you_like_to_see_in_nascar/djvf5vi/