I've been thinking on fitting an after-market reverse parking sensors for my car, and I found 2 options:

  • Electromagnetic


  • Ultrasonic


The Electromagnetic doesn't require to make holes in the bumper, works at shorter distances and it seems cheaper, so it seems the best option.

My question is, is there any drawbacks with the electromagnetic sensors? Are they easy to fit or do I need to go to a garage?

2 Answers 2


I would get a reversing camera instead. You can get the type that is mounted on the license plate and then you can either get a radio/headunit which supports backup cams or get a rearview mirror which has a backup display. Personally I would try to get a rearview mirror one. I think you can get the mirror for about ~$500 with the camera but I don't remember the exact price.

As for the two options supplied I would probably go ultrasonic.

  • Hi @mike-saull. Thanks for the camera suggestion.. I'll search about it, though the option of the rear view mirror is not going to be cheap as I have auto-dimming mirror. Any opinion why you choose the ultrasonic? I read it last less because it's "outside" to weather conditions.
    – SERPRO
    Apr 12, 2013 at 9:24
  • 1
    The replacement mirror is also an autodimming mirror I believe. I am thinking about the Gentex reverse mirrors for example here amazon.com/Gentex-GENK332-Auto-dimming-Hi-Definition-Display/dp/…. The only part that might be expensive would be the install but if you have the ability to install yourself it would not be very expensive. I believe you can get different models which also include compass and homelink in addition to the camera feature. The amazon one I linked doesn't look to have the camera included but you can find those easily.
    – Mike Saull
    Apr 12, 2013 at 19:34
  • 1
    I chose the ultrasonic version because I have had more experience with it personally. My father's vehicle has it and it works well. Although I think it is possible for an electromagnetic version to sense things other than metal I have a hard time believing you could get one powerful enough to fit into the bumper cover and still sense a squishy little dog or something. Seeing is believing though maybe you can test drive a vehicle which has it installed and make your decision that way. I have no prejudices against the electromagnetic version but I would have to see it in action to trust it.
    – Mike Saull
    Apr 12, 2013 at 19:38

My worry about the electromagnetic one is that while it is good at picking up metal objects that you may hit, they aren't so good at organic objects.

Ultrasonic reversing sensors are good at detecting solid objects, but not so good at soft objects.

As solid objects are important to identify, whether or not they are metal, the ultrasonic sensors are, in my opinion, the best ones to install. They are also very cheap, so unless you have cost as an essential priority, ignore pricing as a factor here.

Most home fit kits make the placing of the sensors very simple - the small holes through the bumper are easy to do and will not impact the safety of the bumper in any measurable way.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .