Connects2 CTRCT001 Citroen C2 C3 C4 C5 C8 Car Reversing Sensor InterfaceCTRCT001 Citroen C2 C3 C4 C5 C8 Car Stereo Reverse Sensor Revesring Interface When removing the original head unit and fitting a new aftermarket head unit the audible alert from the original parking sensors will stop working, to overcome this the Connects2 CTRCT001 interface can be fitted which reinstates the reverse parking alerts. Reverse Sensor for the following Citroen models with Blaupunkt Siemens VDO RD4 Radio Installed: Compatible Vehicles