Dension Gateway 500 Porsche Optical Extention Cable Use this extention lead when installing a Dension Gateway 500 in a Porsche with factory CD Changer installed. Use when installing Gateway 500 in Porsche with CD Changer installed. This is a 4 metre fibre extension for the Porsche cayenne when the vehicle has a CDC. Also used on the BMW E90 3 series vehicles when the CDC is installed in the boot. This extension kit will allow you to still use your CDC as well as the iPod. (you must flick the aux switch to toggle between CDC and iPod)