As Caradvice reports, part of this low score comes from the way ANCAP factors in safety assists like lane keeping systems and automatic emergency braking, which the Mustang currently lacks, but there are still some worrying characteristics from the Mustang's crash tests.
ANCAP's CEO, James Goodwin, commented on how the Mustang's airbags failed to inflate sufficiently in the test conducted by Euro NCAP. This means both the driver and the front passenger dummies hit their heads after the airbag bottomed out. "Of concern, the full-width frontal test showed a risk of serious head, chest, and leg injury for the rear passenger. There was also insufficient inflation of both the driver and front passenger airbags in the frontal offset test which allowed the driver's head to contact the steering wheel and the passenger's head to contact the dashboard," said Goodwin. In addition, the side impact pole test caused the driver door to open, and in ANCAP's view there is also not enough whiplash protection in a rear collision. In its tests, the NHTSA views the Mustang as a five-star car.
ANCAP sees safety assist systems as highly important, so much so that the lack of such systems had a major effect on the overall score. The Mustang coupe scored four stars in the Adult Occupant Protection category, three in Child Occupant Protection, and five for Pedestrian Protection, in part thanks to its pop-up hood. The two stars in the Safety Assist category are what undid the overall score.
A Ford rep defended the Mustang, saying that most vehicles in its segment don't offer those systems as standard equipment, while also noting that the updated 2018 Mustang will get new safety systems. Those include Pre-Collision Assist with pedestrian detection, distance alert, lane-departure warning, lane-keeping assist, and Driver Alert System.