Will there constantly be new cars coming out? Like every month, "Ooh! a new Ishibu! And look at those rims..." And another good idea I just had was that there could be a monthly poll as to what car will be made the upcoming month. That'd be cool.
based on Gabester's workflow, I highly doubt it. He tends to finish things in small groups of projects sporadically over time. so he'll have this spell of not much news then he'd suddenly announce a small batch of projects he's been working on that are all at various stages of nearly finished. He even says that he tends to work on multiple things simultaneously so its no surprise that on average, he finishes things in batches. I don't think a regular schedule would work, let alone a monthly schedule.
Well, working on multiple projects at one's pretty hard, I know it on my own experience. It's possible, but it will take more time than working on with only one project, also when switching from one project to another all the time, some times an artist can forget to fix some mesh bugs. I dont know the way Gabester work on his cars, maybe he modeling a Bodyshell of one car and only then start to model another one, or he works on multiple cars at ones.
Personally I've found that switching between different projects can help keep things fresh and reduce tunnel vision, as well as help you spot mistakes when you come back to something. It's a similar concept to flipping an image when painting.
I wouldn't mind seeing monthly content and technical updates provided that its included in the full games price. I would hate to see new cars or parts added with micro-transactions, then again if it follows the Minecraft model pricing wise where new features and items are added for free I would openly welcome new content.