All of the wiring for mine I did behind my left backup light in the trunk lid, you just have to remove the black rug.
I tapped the reverse light bulb for power to the camera, and also again for the reverse signal wire. The RCA for the video and the reverse signal wire were fuse together on my camera wiring, and I ran that through the trunk lid, behind the back seat, and then along the drivers side of the car, under the plastic mouldings, up to the headunit.
Yes you have to remove the liner that on the underside of the trunk lid. Once removed connect red wire from camera to blue revers wire from left back up light along with black wire to black wire for ground. Then run cable along side of back seat up the still plate to the front seat and keep going past fuse panel and make way to back of head unit.
Is this a aftermarket head unit from one company and a backup cam from another company?
My install was all Compass-Nav. Everything was plug and play mins the reverse wire and ground that needed to be spliced into at backup light. No extra wiring needed to be ran that was not included in the box.
On occasions sometimes mine has shown up as a black screen but have the lines on screen. I would move the shifter to out of revers and back in and it would work. Sometimes the park assist lines don't appear and I do the something to get it to work. But I would say 90% of the time it woks first try.
You should have connected your 12v lead from the camera to your reverse light in the rear. Some cameras like the one I used sends the 12v to the camera and it also runs up with your RCA connector to the front. Then you can use that wire to connect up front to signal your monitor to turn on. Otherwise you should had ran the reverse light signal on a separate wire to the front. There should be a connector that comes off the shifter or the BCM. Check the back-up schematic in your ETM to see where to tap the signal from up front. www.hyundaitechinfo.com to get to your ETM for your model car. Good luck!
I just finished adding one to my wife's Sonata. I put a 9" visor monitor in hers.
The visor monitor comes in a LH & RH set. I didn't use the RH and traded it to my local sound shop. Visor monitor set from Amazon. And the camera was about the same cost too. It can monitor two sources for those that want to run a front and rear camera too. If anyone wants to do this, contact me for some tips.