Here are some where IIHS punishes cars that don't meet its features with dubious evidence of improving safety...

Automatic Emergency Braking (AEB) with Pedestrian Detection: IIHS rates vehicles on forward collision avoidance, including pedestrian scenarios, but systems often underperform in real-world conditions like nighttime or with larger vehicles (e.g., trucks or motorcycles). Studies show virtually no crash reduction at night, and features can create false alerts, weather-related failures, or a false sense of security, potentially dulling driver awareness without clear evidence of broad effectiveness at higher speeds.

Roof Strength Test: Vehicles must withstand a force equivalent to a certain multiple of their weight (e.g., 4x for a "good" rating) to simulate rollover protection. Critics, including automotive industry analyses, argue there's no statistically reliable evidence that increasing roof strength beyond basic levels (e.g., from 2.5 to 3.5 strength-to-weight ratio) reduces injury risk, with claims relying on unsupported extrapolations from low-strength data and anomalous results.

Updated Side Impact Test (Introduced 2021): This tougher test uses a heavier, faster-moving barrier (4,200 lbs at 37 mph) to mimic modern SUV strikes. It's criticized for disadvantaging smaller vehicles unfairly, incorporating misleading variables (e.g., tire grip affecting results), and prioritizing structural deformation over occupant outcomes, potentially leading to "poor" ratings despite good dummy readings. Detractors view it as more marketing-driven than reflective of common real-world crashes, with little evidence that the changes proportionally save lives beyond the original test.