Just some of what I can remember off the top of my head: emulate rev limiter: with manual or automatic, when you don't shift (stay on a gear) in real life, and you hit the max RPM allowed by your ECU, it will "bounce off" those RPMs. more highway levels - not really related to the rest, but I feel we don't have enough highway levels, let alone wide road-themed levels with rally- style drifts.
just an FYI before the forum police get here and knock your front door down, all of this has been suggested quite a few times before, especially the fluid leaks and engine/tranny failures. As for now, these are not really planned, especially the fluids, since it would be way to difficult for this to be implemented efficiently. However, I second the motion regarding more highway/wide road maps. You can make your own, although it does take quite a bit of time to make it all right, but there is a small handful of highway mods, Endless Highway, the desert map, etc etc.
With "bouncing" you mean when throttle is cut off at redline. http://youtu.be/sY0xSTalRGk?t=1m13s Here you can hear it at 1:13 when RPM goes up and "bounces" like 1UZ-FE said.
