3rd arg for the call of UpdatePhysics() in PhysicsModule.cs at 123 should be this.LinearVelocity, not this.AngularVelocity (which is, unfortunately, of the same type).
https://github.com/MITLLRacecar/Simulation/blame/bccb61bba165ecb12fd1f6f9abaeeeca455c8fb6/RacecarSim/Assets/Scripts/Racecar/PhysicsModule.cs#L123