work of the warning system. which alerts drivers a collision is coming. with an automatic braking system, the institute says the effectiveness doubles. the top performers, the subaru legacy, outback, cad dak ats and srx, mercedes c plus, volvo s 60 and xc60. without auto brakes damage exceeds $28,000 but with auto brakes less than $6,000 in damage. now compare the two. >> we think it's worth the money. >> we've got two cameras mounted up here. >> reporter: inside the top rated subaru legacy, dominic infante calls the two cameras a second pair of eyes. i was able to take my foot off of the brake and the gas and the car stopped on its own. that's how it was meant to work. >> exactly. so what you've got are two cameras, the cameras are seeing