The passenger compartment of the Q4 e-tron remained stable in the frontal offset test. Dummy numbers showed good protection of the knees and femurs of both the driver and passenger. Audi showed that a similar level of protection would be provided to occupants of different sizes and to those sitting in different positions. Analysis of the deceleration of the impact trolley during the test, and of the deformable barrier after the test, revealed that the Q4 e-tron would be a benign impact partner in a frontal collision. In the full-width rigid barrier test, good or adequate protection was provided to all critical body areas, for both the driver and rear passenger. In the side barrier test, protection of all critical body areas was good and the car scored maximum points in this part of the assessment. In the more severe side pole impact, protection of all critical body areas was good or adequate. Control of excursion (the extent to which a body is thrown to the other side of the vehicle which has been struck on the far side) was rated as marginal. The Q4 e-tron is equipped with a centre airbag to mitigate injuries between occupants in such far-side impacts. The airbag performed well in Euro NCAP's test and protection was good. 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. The Q4 e-tron has a system which applies the brake after a collision, to prevent secondary impacts, and an advanced eCall system which automatically alerts the emergency services in the event of a serious accident.

In both the frontal offset test and the side barrier impact, the Q4 e-tron provided good protection to all critical body areas, for both the 6 and 10 year dummies, 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 used 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 restraint types for which the Q4 e-tron is designed could be properly installed and accommodated in the car.

The protection provided to a pedestrian's head was predominantly good or adequate over most of the bonnet surface. Some areas of weak or poor protection were recorded at the base of the windscreen and on the stiff windscreen pillars. The bonnet provided good protection to pedestrians' legs but protection of the pelvis was poor over much of the width of the car. The autonomous emergency braking (AEB) system of the Q4 e-tron reacts to vulnerable road users such as pedestrians and cyclists, as well as to other vehicles. In Euro NCAP's tests, the response of the system to pedestrians was rated as adequate but its response to cyclists was rated only as marginal.

The Q4 e-tron has a seatbelt reminder system, including occupant detection, on the front and rear seats. 'Rest Recommendation' is a driver status monitoring system which detects fatigued or impaired driving from steering inputs. Speed assistance is provided by a driver-set speed limiter. A speed limit recognition system is available, but is not included in this assessment as it is an option. The lane support system gently corrects the vehicle's path if it is drifting out of lane and also intervenes in more critical situations to prevent the car from leaving the road. The AEB system performed well in tests of its reaction to other vehicles.