FenSens and Pearl RearVision: Backup systems for older cars

10 min read

Backing out of a parking space and parallel parking are probably two of the most difficult driving maneuvers ever. When I took my driving test (over 30 years ago!) I was actually tested on driving in reverse and parallel parking. It wasn’t pretty and it still isn’t. Advances are being made all the time in vehicle safety and it always happens after you bought the car you currently have. It appears that federal regulators agree that backing up is dangerous because both the US and our neighbors to the north will require passenger vehicles built after May 2018 to have a backup camera. Most passenger vehicles already have this feature standard, but what about older vehicles that don’t have this technology?

Many third-party devices are being released to address the lack of backup equipment on older vehicles. I was recently able to test two available solutions.


FenSens (“Fender Sensor”??) consists of a license plate frame with built-in sensors. There is no camera involved. The sensors on the frame connect to an iOS/Android app on your phone via Bluetooth and the app interprets that information and displays it to you on your phone.

The FenSens comes with a variety of security screws. The screws have a non-standard screw head so that they can’t be removed with a standard screwdriver or other standard tools. The tool necessary for installation comes with the FenSens.

The first problem I encountered with the FenSens was that none of the screws provided actually fit the license plate mount on my car. My car is not some oddity. I own one of the most popular “built-in America imports” on the road today. I also found out that the screws that do fit my car are pretty much the accepted standard for license plate mounts. If you walk into a hardware store and ask for license plate screws, they’ll have these screws and won’t have to ask you questions about your car.

Instead of using my own screws, I contacted FenSens and told them that none of the provided screws fit. They were able to send me some screws that did fit and I was on my way.

After I got the correct screws, I was able to install the FenSens in less than 10 minutes. All I had to do was remove my old plate and plate frame and attach the FenSens. The FenSens uses two “AA” batteries which are housed in a box at the bottom of the frame. The battery cover is also held on with some security screws so no one can disable the frame by removing the batteries. According to FenSens, the batteries should last about five months.

The FenSens unit is IP66 rated, so it should do just fine in a rainstorm or car wash. IP67 or IP68 would have been nice, but if your license plate is submerged in 1 meter of water for 30 minutes, you have problems other than a functioning license plate sensor.

The FenSens does include a magnetic phone mount for your car, which I chose not to use because I already have a mount in my car.

To launch the app, FenSens includes a button, which mounts to your steering wheel. You tap the button and the app launches. Tap the button again and the app closes. I found the button on the steering wheel to be very annoying. I’ve been driving for over 30 years and I’m not used to there being a big button in the middle of my steering wheel. I was constantly bumping the button and causing it to fall off the steering wheel. I think it would have been better if it could be mounted to my dash and I could just reach over and press the button.

Downloading the app was easily done. The app wanted me to set up an account with FenSens. I don’t see why this is necessary for a device that’s only going to be used in your car, but I went ahead and created an account and was walked through the rest of the process. The app detected my FenSens unit and the steering wheel button and I had everything up and going quickly.

The FenSens operates via a Bluetooth connection from the frame to the app on your phone.

I should also note that you can buy two FenSens and have one on the front of the car, and one on the rear. This would be great for parallel parking, so you know how close you are to objects both in front and to the rear of your car.

When the app is launched, it will display an area to the rear of your car and emit audible tones. As you back up if there’s something behind you (I tested it by placing a trash can behind the car) the display will indicate the closeness of the object and the audible tones increase in duration. I tried backing up to the large metal “For Sale” sign in my neighbor’s yard, but the FenSens did not warn me. Then I backed up to my neighbor’s car and the FenSens started beeping like a metal detector that just found a pot of gold!

Unfortunately, I only had less than 24-hours to test the FenSens before writing this review. FenSens released an app update that caused me to lose my connection to the FenSens unit. It also caused increased battery drain from the app on my phone. The app also told me that the batteries in the steering wheel button and the FenSens unit were at 0%, which I knew was not the case. I replaced the batteries anyway, and those were also reported to be at 0%.

I alerted FenSens to this issue and I was sent an updated app, but I was never able to get the FenSens to reconnect to the app. I even tried uninstalling and then reinstalling the app, but that did not allow me to connect. I gave up on the FenSens and removed it from my car.

Pearl RearVision

Installation of the Pearl RearVision was just as easy or maybe even easier to install than the FenSens. I had the FenSens removed and the RearVision installed on my car in less than 10 minutes. The RearVision unit consists of a frame that attaches to your plate and mounts it on the back of the car. I actually used the screws from the FenSens to mount the RearVision frame on the car. The RearVision also includes two “feet” that attach to the bottom-inside of your plate and cushions the plate against the plate mounting area on the back of your car. Once you have the frame attached, you just pop on the camera unit and secure it using the included special tool so that the unit can’t be removed unless you have the tool. The special tool folds up and can be stored in your glove box.

The app was easier to set up than the FenSens. There was no need to create a special account in order to use the app.

A magnetic phone mount is included which can either be attached to an air vent on your car or if you use the included adapter, you can permanently attach the mount to your car’s dash. I did not use this mount due to the fact that I already have a magnetic mount in the car. If you have Android, I highly recommend using a magnetic mount. It does not have to be the one that comes in the box, but it does have to be magnetic. I’ll explain why later.

Unfortunately, I was not able to set up and start using the RearVision right away because it lacked a sufficient charge. The RearVision uses rechargeable batteries, which can be charged by solar power or if solar power is not enough, then you can remove the frame and plug in a USB charger to charge the frame. There is no indication of how much charge remains.

The RearVision uses two cameras to show you visually what is behind your car. One camera is a regular camera and the second camera is an infrared camera for night usage. RearVision uses a dongle that plugs into the On-Board Diagnostics (ODB) port on your car. The frame sends the video from the cameras to your phone by way of both Bluetooth and WiFi via the ODB dongle.

The display on your phone can be used in both portrait and landscape mode. I recommend going with landscape. You’ll be able to see more of what’s around you in landscape mode. In portrait mode, you really don’t get the whole picture (pun intended).

The RearVision does alert you audibly that you’re close to an obstacle. The border of the viewing window will turn red and the screen “ripples” at the location of the intrusion to alert you of impending doom.

The RearVision is IP67 so it should do just fine in rainstorms and washing the car. No word on how it acts in below freezing conditions.

Getting back to that magnetic mount. If you use Android, the app is designed to launch as soon as you place your phone on the magnetic dock. It did this with both the included dock and the dock that I already had in the car. If you use iOS or if you don’t use a magnetic car mount, then sorry, you’ll have to launch the app manually. This is where the steering wheel button on the FenSens has the advantage. It’s much easier to press the button on the steering wheel to launch the app and then press again to exit the app. On the RearVision, when you’re done with the app, you must exit the app manually.

RearVision is not without its difficulties. There were a quite a few times that I went to use the app and the connection failed. I also felt that I could just back up and be on my way faster than the app loaded and displayed the video feed. I also feel that the whole process of launching the app and then exiting the app during the act of driving is not safe. If you shouldn’t text and drive, then you shouldn’t be playing with apps on your phone either. I’m not a car expert, but if the RearVision is using the ODB port on your car, then why can’t it tell that your car is in reverse and launch the app and then exit the app when you shift to drive? I also didn’t see how you can get from the camera view to other options and settings on the app. I feel there is much room for improvement to the app’s UI.


After testing both FenSens and RearVision I can definitely see why backup cameras are required safety features. Backing up is not always the safest vehicle maneuver, especially if you’re in a busy shopping center parking lot. Many aftermarket solutions require that you run a wire between the camera on the back of the car to a head unit on your dash. Both the FenSens and RearVision get points for being a wireless solution, but there’s lots of room for improvement. I would go with the RearVision just because of the fact that it uses a camera and the FenSens does not. The FenSens will be the less expensive option. The FenSens is about $149 and the Pearl RearVision is about $499.

Aftermarket solutions may be great now, but if all new cars are required to have this feature, then they’ll be redundant in just a few years.


FenSens on Amazon Pearl RearVision on Amazon