the present invention includes a method of monitoring and controlling interior functions of a vehicle , for example , a memory seat position , a vehicle pedal position , a steering column position , a vehicle interior temperature , and / or whether the vehicle is occupied or unoccupied at certain times and under certain conditions . the interior functions are controlled by passively monitoring a characteristic of an occupant , determining an identity of the occupant based on the monitored characteristic , and regulating the interior function based upon the identity of the occupant . the monitored characteristic , for example , may be representative of a weight classification or biomass associated with the occupant , or a signal or input generated based upon a user identification device , for example , a key fob or other personal electronic device carried by the occupant .