The OPi-P with AUX kit adds iPod control and composite audio auxiliary audio to the factory fiber optic system in select Porsche vehicles. 

The OPi-M with AUX kit adds iPod control and composite audio auxiliary audio to the factory fiber optic system in select Mercedes vehicles. 

The OPi-A with AUX kit adds iPod control and composite audio auxiliary audio to the factory fiber optic system in select AUDI vehicles.