It sits above the rearview mirror and provides a wide-angle view of the backseat. It's standard on the Honda Odyssey and Ford Freestyle.
Safe? Yes. Because you're used to glancing at your rearview mirror, looking at the additional one should be an easy adjustment.
Sliding second-row seats
Moving the middle seat in the second row forward makes it easier to hand your child a snack or a tissue. It's standard in the Toyota Sienna 8 passenger, the Volvo XC90 SUV, and the Ford Expedition.
Safe? Only you know if you'll be unnerved when he shrieks in your ear as you're turning into traffic.
LCD video monitoring
Companies like Rostra Precision Controls sell interior video cameras that project the backseat action onto a screen in a new rearview mirror.
Safe? No. Though it lets you monitor a rear-facing child seat, the tiny screen could distract you from the road. Best not to watch TV while driving, even if your child is what's on.