1. A method of configuring a speech recognition unit in a vehicle, the method comprising: receiving a noise error from the speech recognition unit responsive to a user voice command; and carrying out at least one iteration of the following steps: reducing a confidence threshold for an appropriate grammar set responsive to the received noise error; and re-attempting speech recognition in the vehicle using the reduced confidence threshold; wherein the reducing and re-attempting steps further comprise, during at least one iteration, the steps of storing the voice command prior to the reducing step and then, after the reducing step, attempting speech recognition in the vehicle on the stored voice command using the reduced confidence threshold.