So I finally found one that looks like it was meant to be there!I bought these from eBay:
Camera: http://www.ebay.ca/itm/NEW-SONY-CCD-Car ... 3cc4c3c816" onclick="window.open(this.href);return false; (search for "backup camera toyota rav4")
Mirror with monitor: http://www.ebay.ca/itm/New-4-3-4-3-Inch ... 3377abed43" onclick="window.open(this.href);return false; (any monitor will work)
The camera is (almost) a direct replacement for our license plate lamp. I had to shave one of the openings for the light bulb tabs, but that was fairly easy. I have the GT, which has a different bumper from the other trims, but it's probably a safe assumption that this part is the same.
To install it, I had to remove all the covers, spare tire and compartments from the cargo area. I punched a hole in the rubber grommet going to the bumper. It had to be quite a substantial hole because of the RCA connectors from the camera. You can squirt some silicon on it after to make sure it's watertight. Connected the power for the camera to the reverse light and ran the video signal cable under the sub-woofer, down the rear passenger side door, along the kick panels to the front, up the A-pillar and over to the rear view mirror.
For the mirror, I got power from the mirror connector. The yellow wire is accessory power and the grey (or brown according to the service manual) is ground. I found that the wire didn't have enough juice to power both the old mirror and the new mirror at the same time, so I just unplugged the connector from the old mirror since I don't have OnStar anyway. The jumble of RCA connectors off the mirror made it impossible to hide in the headliner, so I just taped up the bundle and zip-tied it to the original mirror harness.
Here's a picture of the camera. You can hardly see it and it looks like it is from the factory.
Here's the mirror.
The distance markers are from the camera feed, not the monitor. They are: STOP, 0.5m, 1.5m and 3.0m. At STOP, the distance is about 1 foot. At 0.5m, it's about 0.5m, give or take a few cm. But the 1.5m and 3.0m are way off. At 3.0m, it's only about 1.2m. This is because the license plate on a RAV4 is much higher than on a Vibe. It's a minor issue, but the big benefit is that I can see if there's anything on the ground behind the car.
I'm not as impressed with the mirror monitor though. When I'm not in reverse, the mirror is quite dim. It looks like a dimmed auto-dimming mirror, but all the time. And when the video is shown, there's still quite a bit of glare. I think I'll use it for a while to see if I get used to it, but I'll probably pick up an in-dash NAV system (I figure if I'm going to get an monitor, might as well get NAV too) if I come across a good deal on one.