Real or not, I gotta say that having those sounds would make the game more injoyable.
I also like the idea of a previous poster about having to warm the engine.
There is so much yet that can be added, selecting what I would like first is difficult. If forced to chose, I would say roads and bridges for the ground vehicles vs the spawn point 2 miles from a base.
Don't want to hijack the thread so I'll stop here. Oops, maybe I already did. Sorry.
Weave