For enhanced safety, the front and rear seat shoulder belts of the Volkswagen ID.4 have pretensioners to tighten the seatbelts and eliminate dangerous slack in the event of a collision and force limiters to limit the pressure the belts will exert on the passengers. The Toyota Prius Prime doesn’t offer pretensioners for the rear seat belts.
The ID.4’s pre-crash front seatbelts will tighten automatically in the event the vehicle detects an impending crash, improving protection against injury significantly. The Prius Prime doesn’t offer pre-crash pretensioners.
Both the ID.4 and Prius Prime have child safety locks to prevent children from opening the rear doors. The ID.4 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 Prius Prime’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 ID.4 has a standard Automatic Post-Collision Braking System, which automatically applies the brakes in the event of a crash to help prevent secondary collisions and prevent further injuries. The Prius Prime 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.
The ID.4 has all-wheel drive to maximize traction under poor conditions, especially in ice and snow. The Prius Prime doesn’t offer all-wheel drive.
The ID.4 has a standard blind spot warning system that uses sensors to alert the driver to objects in the vehicle’s blind spots where the side view mirrors don’t reveal them and moves the vehicle back into its lane. Only the Prius Prime Limited offers a blind spot warning system.
To help make backing out of a parking space safer, the ID.4 has a standard rear cross-path warning system, which uses sensors in the rear bumper to alert the driver to vehicles approaching from the side, helping the driver avoid collisions. Only the Prius Prime Limited has a rear cross-path warning system.
Both the ID.4 and the Prius Prime have standard driver and passenger frontal airbags, front side-impact airbags, side-impact head airbags, 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, rearview cameras and driver alert monitors.
The Volkswagen ID.4 weighs 1193 to 1562 pounds more than the Toyota Prius Prime. The NHTSA advises that heavier vehicles are much safer in collisions than their significantly lighter counterparts.
For its top level performance in IIHS driver and passenger-side small overlap frontal, moderate overlap frontal, side impact, roof strength and head restraint tests, its standard vehicle-to-vehicle front crash prevention system, its standard vehicle-to-pedestrian front crash prevention system, and its standard headlight’s “Good” rating, the Insurance Institute for Highway Safety grants the ID.4 its highest rating: “Top Safety Pick Plus” for 2021, a rating granted to only 76 vehicles tested by the IIHS. The Prius Prime last would have qualified as only a standard “Top Safety Pick” for 2019.