Multiplayer input conflicts

Wondering if someone could give me some insight on this problem here..

I am making a multiplayer racing game and when I have two clients connected to a server (one is client/server the other just client) I seem to be getting input conflicts from each client.. Basically the client's mouse input is affecting the wheels on the other clients vehicle.

I can tell exactly if their inputs are getting added together .. or if they are both running of the same mvYaw variable (which they shouldnt be) or what the heck is going on...

Didnt know if someone has already encountered something like this..

thanks.