R@S,
Being able to upgrade vehicles sounds like a VERY cool idea. I like it a lot.
I have no idea how the Hard Life Addon implemented "breakdowns," but even that sounds intriguing to me. "Improve" a vehicle too much in one way, such as by adding too much armor, and it eventually breaks down due to the suspension system not being suitably upgraded to handle the extra load (such as the constant breaking down of uparmored Humvees in the Iraq/Afghanistan occupations). One might have to first wisely upgrade one system before improving another.
But I could see where all of this micro-management could get too cumbersome, yet if it was setup so that the potential negative consequences of adjusting a vehicle could be completely avoidable by simply never choosing to participate in any special enhancements, then it would be up to the Player as to whether or not he/she wanted to dip a toe into those waters.
Players who are "into" this kind of thing would love it. I certainly would.
The upgrades could start out more simply, and with fewer negative consequences, such as being able to swap out the standard engine for something more powerful, allowing a vehicle to travel faster and to carry more weight.
The same concerns exist with the larger economics system tied into the towns and cities. Taxation and the like sure sounds interesting to
me, but if I had a penny to gamble with, I'd wager that most of the community members would more greatly appreciate an increase in missions and campaigns, both in number and in depth (fleshing them out more, such as by adding on even more possible consequences for the choices one makes).
That said, for those who enjoy the more free-form way of playing, expanding on the economy and its relationship to capturing/maintaining territories, would be right up their alley, as would opening up a universe of possibilities by adjusting their vehicles.
Happily for me,
I like it all. I'm just surmising what the other members may be more itching for.
Like more entry zones and randomized enemy patrols (subtle hint, REALLY!).
Have to go. Studying to do.
Go microeconomics!