I have found the rear backup camera quite useful. In rain/fog you still see well enough. In snow you see what you need to as well. The best thing is to be sure the cam face is cleared off if your brushing snow off the car. It has saved me once already...so I do like it. The more I use it for backup, the more I appreciate it. I can even see the side of my garage and it approximates the bumper location accordingly and I have not hit it yet....as a result!
If you can see out the back window, the camera can see what you see. It may have a few droplets of water or a few small flakes on the camera but you get the general picture. You don't need a clean camera lens to see what's behind you if something's that close. So far, I've been impressed. I was worried that I'll be dealing with a dirty camera (as in completely covered in dust/snow/dirt etc) given that the back of the car always gets dirty (vacuum and aerodynamic effects) but even after driving on a country road with some loose snow on the road and the back of the car all white, it still works and I could see where the side lane is where I was making a u-turn and backing into that side lane. The lower rear window wasn't of much help.
Really starting to like the camera. At night the reverse light gives enough light to be able to see with the camera pretty well. Reversed out of our friends drive last week as easy as pie, usually finish up turning both side mirrors down to see, but no longer. Also the various guidelines etc are a real help. Usually find the red line on the camera is on the front of the car or wall behind well before the reverse sensors start beeping faster. Have not noticed the back of the car, and hence the camera lens, being dirtied by spay ans slush sucked up onto the back. Air flow seems to be very well sorted out back there. Used the front sensors today and parked a lot closer. Chickened out before continuous beep and still had at least a foot to go. David
My friend has a 2007 BMW X5 so I've gotten to see his backup camera and I must say that the 2010 Prius backup camera is much better, especially at night. I do wish that we had the angle of approach lines superimposed on the screen, but even without that I prefer my camera to his (he's even commented that my camera is better than his).
This looks like the best way to go. Have you installed a electromagnetic sensor system yet? We also live in the bay area and I'm looking for a US source( most likely made in China ) for a system. Good luck.
More than a parking sensor, how about Blind Spot sensors that warn of a car in the blind spot. Ford has an amber warning light appear in the outside mirror when a vehicle is present where you can't possibly see it. Now THAT is something useful ! I'm an old New York City driver so parallel parking into tight spaces is routine for me, and the parking ability of the Prius when set on the automatic parking needs much more space than I'm accustomed to having.
A few years ago, I started adjusting my mirrors differently to reduce the size of my blind spots. Most people adjust them so that you can see the side of the car; this produces a lot of overlap between the side mirrors and the rear view mirror. If you adjust them the same, but put your head near the window while adjusting the left mirror, and over the center console while adjusting the right mirror, they will aim out significantly further. This adjustment makes it almost impossible for a car to be in your mirror's blind spot without also being visible directly left or right. It took some getting used to, though; you can't change lanes by only looking in the side mirror, as you can't see nearly far enough back. And it's strange at first not having very much overlap between the side and rear view mirrors. And of course, you still have to check your blind spot by looking over your shoulder.
Blind spot: 3" convex mirrors on the inner top portion of my side mirrors. I can also now see the curb when i park. My Sienna really has the best coverage for parking...it has front side sonars and full rear coverage sonar PLUS rearview camera. You can't do wrong in the Sienna!
