A system, apparatus, method and computer program product to obtain comprehensive vehicle radio listener statistics based on parameters such as radio status (e.g., on/off status and CD/Tape/AM/FM setting), radio volume, station preset information, current frequency setting (i.e., station identification), and Global Positioning Satellite (GPS) system coordinates is disclosed. A vehicle-mounted field unit for collecting and transmitting such parameters to a base station is also disclosed. The system monitors and stores all events related to the occupants' interaction with the vehicle's radio, including automatic detection of the selected radio station through a speaker port. The stored data is then transmitted to a base station's central collection computer for immediate compilation and analysis. The system is capable of producing detailed reports containing error-free, unbiased, audience measurement statistics which can be made available to subscribers such as broadcasters, corporate advertisers, advertising agencies and the like.