For the past four years, the non-profit Consumer Reports has been putting child car seats to the test. Their goal is to "differentiate car seats that provide an additional margin of safety above the basic level already provided. Child restraints must meet a federal standard to be sold in the U.S." When put through the testing, several seats had alarming results.

Four models actually had parts break during testing. Some of the harness systems that would hold the child in place were damaged during trials with crash dummies. In a bad accident, these issues could cause a child to be ejected from the vehicle.

Seats are evaluated for their crash protection on a scale of Basic, Better, and Best. All four of these seats score a “Basic” for crash protection - Britax Frontier ClickTight, Britax Pioneer, Cosco Finale, and Harmony Defender 360.

To read more about the study and each car seat, click here.