The camera I installed is a Boyo VTK350.
The short story is... Remove the license plate trim assembly, drill the hole where you want the camera, mount the camera, re-install the trim assembly with newly installed camera, and wire it.
To answer your question, there is no need to drill out material from the actual trunk lid. As you can see in the image below, there is an equal amount of depth underneath the license plate trim.
With the camera mounted on the trim, only about 1/2 of that depth is used, as shown in the next image.
I hooked up this reverse camera to my navigation system (Pioneer AVIC-Z3). In order for the deck to automatically switch to the reverse camera when you put the car into reverse, you need to connect the reverse trigger (typically a purple wire) to your reverse light wire. I ran the purple reverse trigger line all the way to the rear left side of my trunk, where there is a connector for all the lights in the rear section of the car.
This is how I hooked up the reverse lead....
I disconnected the connector and removed the left reverse light wire/pin (GRN/BLK).
I routed the reverse signal wire coming from the navigation deck through the center consoles, under the passenger side rear seat, across the back of the trunk and through the wire loom that leads to the main connector.
I soldered the reverse wire to the very tip of the GRN/BLK pin that I removed.
I re-installed the pin with the reverse signal wire soldered to the GRN/BLK reverse light wire.
Clean.
I always 'tap into' my wires like this. I don't like using those crimp connectors. If for any reason I ever want to remove any wires I might have tapped into, the wires are left partially cut, damaged, and/or weakened. This way if I want to get rid of any wires or devices that I tapped into, all I need to do is touch a hot soldering iron to the pin and remove it. No damage done.
There is actually quite a bit of custom wiring here. LED spoiler light, reverse camera wiring, and some lighting. I like to keep my wires tucked away in OEM style wire looms.
Not super detailed…. But here is a very basic walkthrough. I think it should be enough in pointing you in the right direction in doing this. If there are any details you’d like to know about, just ask in this thread. Forgive any incorrect terminology. =P
STEPS:
1. Open your trunk all the way up. Above your license plate, there is a plastic screw. Carefully loosen the screw and remove it. After removing the screw, remove the black platic piece that the screw goes into. (#41 in the image below)
On the backside of your trunk lid, on the other side from where your license plate is, there are 4 nuts holding the license plate trim assembly to the trunk. Remove the 4 nuts. After all 4 nuts are removed, there are 2 self-locking tabs toward the top center and bottom center of the trunk lid (number 35 in the image above). Push the locking tabs together from the inside of the trunk and push up on them one at a time until the license plate trim pops out. Pull out the trim assembly.
2. Now that your trim assembly is out, you can decide where you want your camera. I chose to have it at the exact opposite side of the trunk key. I was thinking of putting it below the key hole, but then decided not to... It's up to you.
***IMPORTANT*** The camera must be mounted at least 1cm in from the edges of the license plate trim assembly to clear the trunk lid.
3. Once you drill the hole, mount the camera. If you use the same camera (Boyo VTK350), you can choose to mount it aiming straight or at an angle (up, down or to the side). There are angled mounting pieces included with the camera. I aimed my camera straight.
4. Put the license plate trim back into its mounting holes but DON'T "snap" it in yet! You have to align the camera. If you already did the wiring for your camera you can use your existing wiring, otherwise, you'll need to run some temporary wires to your battery and reverse camera monitor. Either way, get your camera connected to your monitor and adjust it so that it is level. When I did this, I tightened my camera just enough so that if I want to, I can push on it and turn it a little if I want to fine tune the camera's level later.
5. Once leveled, you have to run your wires through the trunk. You will have to drill a small hole to route your wires. I drilled a hole directly behind the camera. After drilling the hole, I painted over the bare metal edges to prevent rust, let it dry and THEN ran the camera's power and video wires through the hole. Once you ran the wires through, you can fully installed the license plate trim by snapping it into place and securing it with the 4 nuts you removed in step 1.
6. Since you drilled a hole in the trunk, you'll want to do some water proofing. I just put weather proof calking over the hole I drilled from the inside of the trunk.
7. Run the wires through the trunk lid alongside the trunk release cable down into the actual trunk area.
As far as powering the camera, I just wired it to my ignition power. When I turn my key to IGN, the camera turns on. I did it this way because the reverse light turns on in IGN not in ACC mode. I just tapped my cameras into my cigarette lighter. I also have a secondary camera, which I am still deciding on where to mount… Maybe on the side of the car behind the front wheel or something…
I will leave wiring the camera to power up to you. I’m assuming that is a very basic thing most people know how to do. If you have any questions about that, feel free to ask away in this thread.