As of May 2015, websites for Amazon.com and Costco.com publish reviews for wireless back-up cameras. In addition, both sites have five-star rating systems so reviewers are able to score cameras.
Amazon.com reviews cover wireless back-up cameras with various sizes of monitors, including 3.5-, 4.3- and 7-inch displays. Positive comments mention how easy the cameras are to install and praise the clarity of the rear view. On the other hand, some reviewers state that the devices are not water-tight, and they pick up a lot of interference. Top reviews on Costco.com mention the wide viewing angle and reasonable price. Negative findings include insufficient instructions and mirrors that are too dark.