The passenger compartment of the ID.4 remained stable in the frontal offset test. Dummy readings showed good protection or adequate for all critical body regions of the driver and passenger. VW showed that good protection would be provided also to the knees and femurs of occupants of different sizes and to those sitting in different positions. Analysis of the deformable barrier used in the frontal offset test revealed a small area of high deformation. However, the deceleration profile of the trolley on which the barrier was mounted showed that the ID.4 would not be an aggressive crash opponent. In both the side barrier and side pole tests, the car provided good protection to all critical body regions and scored maximum points. Occupant excursion in a far-side impact was rated as weak. The ID.4 has, as standard, a centre-mounted airbag which protects the driver and front passenger from hard mutual contact in the event of a side crash. Euro NCAP's test showed that the airbag offers good protection for the heads of the front occupants. Tests on the front seats and head restraints demonstrated good protection against whiplash injuries in the event of a rear-end collision. A geometric analysis of the rear seats also indicated good whiplash protection.

In both the frontal offset test and the side barrier test, the ID.4 provided good protection to all critical body areas of both the 6 year and 10 year dummy, and scored maximum points in this part of the assessment. The front passenger airbag can be disabled to allow a rearward-facing child restraint to be fitted in that seating position. Clear information is provided to the driver regarding the status of the airbag and the system was rewarded. All of the child restraint types for which the ID.4 is designed could be properly fitted and accommodated in the car.

The protection provided to the head of a struck pedestrian was good or adequate over most of the bonnet surface, with some poor results recorded only on the stiff windscreen pillars. The bumper provided good protection to pedestrians' legs at all test locations. Protection of the pelvis was good or adequate at all points tested by Euro NCAP. The autonomous emergency braking (AEB) system of the ID.4 can detect pedestrians and cyclists. In tests of its response to such vulnerable road users, the system performed adequately, avoiding or mitigating collision in most test scenarios. The ID.4 cannot detect pedestrians to the rear of the car and AEB-reverse tests were not performed.

The ID.4 has a speed assistance system as standard. This uses a camera and digital mapping to determine the local speed limit and the driver can choose to allow the system to adjust the speed automatically. A seatbelt reminder is standard for all seating positions. A fatigue-detection system monitors driver alertness and issues a warning if impaired driving is detected. Lane assistance warns the driver if the car is drifting out of lane and gently corrects the vehicle path. The system also intervenes more aggressively in some more critical situations. The AEB system performed well in tests of its response to other vehicles, with collisions avoided or mitigated in almost all scenarios.