I do like the idea of the game just stopping progression at 2020, but still being able to play; as in reaching 2020 and no new tech comes out; however, you can still develop your company further to emulate later years. The devs have said that each tech point is like a year ahead, provided that you can still go beyond 2020 using those tech points, you can reach a point at which all of your sub-assemblies have tech pools of 15, your company is using the largest, most efficient factory, and you are at max output; at this point, I can understand the game stopping.
However, even then, I would like a way to have the opponents keep releasing cars, and you keep releasing cars, for all that tech doesn't advance more. Simply playing it like the ultimate sandbox, as the way I seem to understand it is the sandbox in game currently will only ever be for creating cars, not selling them, as that would be cheating to know how the car will sell! On the other hand, when you no longer care about losing the game anymore, you can create wonderfully radical designs, which may fail and may succeed; you could still have the public changing their tastes and thus develop your playing style more; you can still have fun, and at the end of the day, isn't that the point of the game?
Provided that it doesn't break the game of course.
As for what the other people are saying: It seems like what you guys are struggling with is the idea of developing your company for so long, working so diligently at making it successful in its niche, and then having it just disappear. I agree with this, in that it would be a problem. In the last 5-10 years, immersion would be broken; you would be rushing your cars in the last year, hurting their successes not because things which should dictate decisions such as these, but external, non-immersive things such as the year limit. If we end up with such a limit, at least for me personally some of the enjoyment would be gone at the end game.
You guys know how important immersion is; that is why games like Detroit and Car Tycoon failed; bugs, bad ideas, anything that breaks a game thus breaks immersion and breaks the enjoyment. Heck, Wolfenstein is not realistic at all and still manages to be immersive! To get the everyday person into Automation and not just the car guys, people need to get into their companies; you cannot rely on just the fact that you are creating and selling your own products to keep people interested, but the fact that they put real thought into their company's success because they want it to succeed because they are immersed into the story of their companies, for the fact that they want to beat those competitiors that are always releasing those annoyingly good cars, for the fact that they want to help the environment or set a new speed record, for the fact that they want to succeed because they ARE the company, rather than being the player!
Well, I should look at who I'm preaching to

You guys probably know exactly this already.