Quality control is not easy for a sim open to mods. It' not possible yet to restrict user modeled cars to real physical behaviour. In a perfectly simulated environment, bad mods would behave badly and unrealistic ones could not be used at all. I don't see that kind of simulation being feasible on home computers for the next ten years.
Maybe somwhen inbetween, premodeled parts could be made avaiable to build cars, but then it's more of a building simulation. After S3 is finished, the developers may start creating "Live to build" and then start an online engineering community that builds cars for S4.
Even with premanufactured parts, it's hard to avoid bugusing... this would be rather hard to achieve.
It's a shame that so many people out there would certainly build unrealistic, overpowered cars that will ruin the whole LFS experience to others. It's also a shame that there are people out there who can build better cars than the ones included in LFS (more time, no money considerations, ...) - that effectively can't be used because of the more or less crappy other mods.
One possibility to solve this is to allow only approved mods to race online. But then again the approval process would have to be very strict, leading to frustration on both sides and endless flamewars on the forums. Doesn't sound too convincing to me.
I don't think that real cars should be included in the game, if that costs money. That money should be used to improve the simulation. I bet that when S3 comes out, some more (small) manufacturers actually want to be included in the game
No, not more real cars, but more realistic (and detailed) models of the ones we have now. If they appear to be real, they become real. Then people wish to have those cars in front of their house, and not only in the computer.
All in time.