A decade ago automakers equipped few vehicles with back-up cameras. But in December 2010, federal transportation officials issued a proposed rule that would require all new automobiles to have backup cameras by September 2014. The mandate, which has been delayed repeatedly, was spurred by the alarming number of children who die or are injured every year in back-over accidents. It’s estimated the cameras would save 95 to 112 lives a year. Though the rule is not in effect yet, more and more vehicles are carrying the safety feature. Here are 40 vehicles under $30,000 with the cameras.