I was just on an international server with a full grid and 40+ connected (ping 340ms from here, and I'm on a 384kbps line) and I must say, a big thumbs up! Whatever's been done has gone a long way into reducing jitter! I've just got two more suggestions to reduce it further (maybe, assuming they're feasible and they've not already been done,
) - perhaps, rather than just sending a value for the position of the steering wheel, include a rate of rotation in the packet, this might help smooth out jitter due to violent wheel movements. Also, would it be feasible to store an approximated brake point for each corner (maybe for each driver in the field too, if necessary) and attempt to reduce the jump caused by a driver stepping on the brakes in a laggy situation? If it would help deal with such issues, I could maybe save a few replays from servers at these pings?