The Q4 e-tron’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The RDX doesn’t offer pre-crash pretensioners.
Both the Q4 e-tron and RDX have child safety locks to prevent children from opening the rear doors. The Q4 e-tron has power child safety locks, allowing the driver to activate and deactivate them from the driver's seat and to know when they're engaged. The RDX’s child locks have to be individually engaged at each rear door with a manual switch. The driver can’t know the status of the locks without opening the doors and checking them.
The Q4 e-tron has a standard Secondary Collision Brake Assist, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The RDX doesn’t offer a post collision braking system: in the event of a collision that triggers the airbags, more collisions are possible without the protection of airbags that may have already deployed.
Both the Q4 e-tron and the RDX have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, front seatbelt pretensioners, height adjustable front shoulder belts, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, crash mitigating brakes, daytime running lights, lane departure warning systems, blind spot warning systems, rearview cameras, rear cross-path warning and available around view monitors.
The Audi Q4 e-tron weighs 616 to 1086 pounds more than the Acura RDX. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.