Crash guards usually causes problem with Airbag deployment prevents bonnet from acting as crumple zone and impacts the chassis of the car badly which is more harmful for passengers according to this source

In the case of rear of hatch back car , there's no crumple zone such as big boot space and there's no air bag sensor on the behind so having a crash guard does more good than bad.

Can someone share their insights on this please ?

  • Please explain what you're asking about. Every car I have ever owned has had both a front and a rear bumper installed from the factory.
    – jwh20
    Commented Apr 22, 2023 at 20:48
  • I've updated my question. Commented Apr 23, 2023 at 8:02
  • 1
    I dispute your premises. One, every vehicle has body structure and sheet metal further back from the location of the rear wheels. This serves as a rear "crumple zone." Whether a specific vehicle is as good as another will depend upon the design of the specific vehicle. Two, airbag sensors react to sudden unexpected acceleration or deceleration of the car body; the sensor's location within the car body is irrelevant. All in all, this seems to ask for discussion, and not opinion. This site seeks questions with declarative answers, not discussions. I voted to close as opinion-based. Commented Apr 23, 2023 at 8:55
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    You are incorrect in assuming a hatchback has no crumple zone at the rear. They do have them. Also, your assertion that a 'big boot space' is a crumple zone is incorrect. A boot is not a crumple zone.
    – Chenmunka
    Commented Apr 23, 2023 at 16:45
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    No - it likely won't be helpful. It will likely make a crash better for the vehicle, but worse for the occupants. Personally I'd rather permanently wreck my car than permanently wreck my spine.
    – James T
    Commented Apr 25, 2023 at 12:44

1 Answer 1


No, it's generally not a good idea.

The manufacturer spends vast amounts of money and development time in building in proper type-approved crash protection. Randomly adding girders will transmit the forces of the impact to different places, potentially making things far worse.

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