The system has been working flawlessly since being installed two months ago. However, I did manage to lose the remote (blaming that on my 4 & 5 yo kids). I sent a message to the seller, and the shipped me a new on (no cost) from China, no strings attached.
A couple of weeks ago the front camera started displaying a rainbow/interference/noise over the video signal. I contacted Weivision and they immediately replied with some troubleshooting suggestions. However, by the time I had a chance to try them, the problem resolved. Then, last week, the rear camera went to all yellow. I un/re-plugged all the harnesses from the camera and main unit, but the problem did not resolve. I took a picture of the screen, and sent it to Weivision. Despite it being the weekend, they replied within a few hours, and are sending me replacement cameras! Incredible service!
While it'd be best if there were never any issues, sometimes it's only through these problems that you get to know a seller and how they treat their customers. In this case, I'm very impressed with their speed and generosity.
ORIGINAL REVIEW 12-15-18:
I installed this on my 2011 Sequoia Limited. I had previously replaced the stock head unit with a Hizpo Android head unit - which provides a larger, clearer screen, and WAY more functionality than the factory radio.
Installation took about 5 hours, spread over two days. I could have done it in half that time, but I was being very particular about how to run the cables, leaving no trace of the installation. The supplied cables were just long enough to reach the main unit - which I installed under the passenger seat. The cable to the rear camera had about 6" of remaining length, so it was very close.
The rear camera is exactly the same size as the stock backup camera. Though, the mounting points are not. That meant I was able to pop the original camera out, and 'glue' the new camera in its place using double stick tape (to hold) while black caulking dried. There was no trimming or cutting needed, so everything is reversible.
The side camera mounts were tricky and required dismount of the mirrors so I could run the cable in the existing chase. The efforts paid off, as now there is no sign of the install (other than the cameras).
The front camera was mounted below the hood grill, on the bumper. I did this to avoid any possible vibration, since the grill itself moves with the hood.
I ran an extra coax/RCA cable from the back of the head unit to the passenger seat, as well as constant (battery) 12V, accessory 12V, the remote trigger wire (used to tell the radio to switch to rear input), and a reverse signal wire (to tell the Weivision unit that the truck is in reverse).
None of the wiring required cutting/splicing factory wires. There were no changes made to any part of the vehicle (other than the holes in the side mirrors) that cannot be reversed.
Calibration was a bit tedious due to windy conditions. Ultimately, I ended up moving the vehicle into my barn where I had better control of the environment. And that seemed to work, as the cameras display just as good as my wife's 2018 Highlander Platinum, and its factory surround view.
In fact, I like this unit better because it has the following features which the Toyota surround does not:
1) Recording all channels. Imagine being accused of running a red light. The front camera catches the instant the light turns red. The side cameras, which record the placement of your front tires, show exactly where the wheels are relative to the stop bar as the light turns. Priceless... And I don't run lights.
2) Turn signals switch views to that side of the car. That makes it ideal when trying to squeeze through a narrow spot, or if you need to see exactly how close you are to a curb/item.
3) Digital adjustment of individual cameras. Each view can be manipulated (without affecting the surround view stitched image) to meet your expectations. Want to see more of the trailer hitch than the person's face in the car behind you? Simply adjust the view down with the remote.
4) Vibration recording even when parked. If someone bumps your car while it's parked, the unit wakes up and starts recording. Thus, even when you're not there, it will monitor your vehicle like a security guard.
I'm sure there are more upsides to this that I haven't found yet. But for the money, this is probably one of the most practical and safety-minded things you can add to a vehicle. I'm seriously considering adding one to my Tundra (which I rarely drive).