Rear Camera via AUX

[z350convert]

2011 Roadster

I've got my after market rear view camera working on the factory head unit via the AUX input. It’s ok but cuts out when car is moving. HOW DO I WIRE IT INTO THE PROPER CAMERA INPUT ON THE BACK OF THE HEAD UNIT PLEASE?

Thanks 

[EvansJD2112]

Your aftermarket HU should have an input for the camera and a trigger cable. Separate to the aux input