Due to shortcomings with the HL2 engine it seems that we're going to have to put this mod idea on the shelf for the unforseeable future. We've run into the same issues that the HL2 Rally team did. Here's a quote from their site:
HL Rally 2 Closure
27/12/2006
HL Rally 2 will no longer be developed due to problems and limitations of the Source SDK.
Some of the critical problems we experienced were:
-Vehicles were controlled by the server making them latent and not fun to play on the Internet
-Predicting the vehicles on the client failed as the client and server simulate the physics differently, causing the vehicles to get rapidly out of sync
-Correcting the predicted vehicles position made the game feel unresponsive and caused the vehicle to travel unexpected paths
-Valve themselves said that it was currently impossible to predict and therefore network vphysics objects accurately (think of the barrels in CS).
-The SDK does not allow for direct modification of physics
-Could not implement manual transmission due to SDK limitations
-RPM calculations were erratic and more often than not incorrect
-RPM values could not be recalculated accurately
-Resultingly, we have decided to cease development on the mod and release parts of the source code to see if other modders can potentially overcome this issue.
