I've been thinking lately that it would be really cool if there were more auto manufactures in Nascar. I remember a rumor a few years ago that companies like Nissan and Volkswagen were looking for a interest in Nascar. We need a bit more variety. :3
If anything, the existing manufacturers should provide more models to race in the series we already have, like running the Sierra alongside the Silverado in the Truck Series, Toyota running Lexus models in Xfinity, etc.