More thoughts -
First and foremost, you want to make sure this works!!! I know the pictures show it working and I assume the company might have used your camera and your head unit to test it. But there is very little worse than making a post and getting say 10-15 orders for these, and then finding out it won't work with some cars and having to refund customers money (and then the company gets a reputation for not making good products and the fact that the initial ones were bad and the later ones were great doesn't matter).
Also - I'm curious how the Steering wheel controls work with it.
For example - this is the standard corolla HU replacement process:
Get new head unit and Metra 95-8245 Dash kit to install radio.
Get Metra 70-1761 Harness to power radio.
Get Metra 40-LX11 Adapter to connect antenna.
Get Metra 80-8114 Harness and ASWC-1 Interface to keep steering wheel controls and AUX port.
Either splice and convert existing wires, or install aftermarket video camera.
Either splice and convert existing wires, or use head unit USB as OEM won't work.
Use head unit BT interface as Toyota BT mic won't work.
Install aftermarket Sirius Tuner as OEM will be removed.
Now - the key point is the ASWC-1 -
http://www.metraonline.com/files/products/ASWC-INST10_web.pdf - There are basically 15 different settings on the ASWC-1 for different types of OEM radios. If your harness uses the ASWC-1, it is probably fine. If it doesn't, your harness might work great with a Pioneer, but not at all for a Kenwood - so either you have to make separate Pioneer/Kenwood/JVC/Sony/Clarion harnesses, or you need some type of selector module in your harness (or you make the harness for Pioneer only and specify that it works with an AVH-3400 and should work with other Pioneers, but use at your own risk with anything else.