I probably would not have purchased a back-up camera but one came with my last truck purchase.
This is a 2010 F150 truck and has a console system video screen that also works for the rear camera which is mounted in the FORD Emblem on the rear tail gate.



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I can actually see the trailer hitch ride right over the ball hitch when backing up. First time every time... I also have feet makers on the view screen that tells me how far away the items in view are at...
The only drawbacks I have is at night as outside light sources seem to make the view on the console screen flare up. Makes things hard to see. Another draw back is when it rains. Large water drops appear on the screen making it hard to see things...
Of course it only comes on when the truck is in REVERSE position so will not be working when driving down the roadways... I am real sure that if the rear camera was ON at night it would be impossible to use when approaching cars come up behind on the roadways... The only way to make something like this work at night would be to install the rear camera up very high and be pointing down at a large angle. Something like this rear trailer install...

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After having it for a few years now it is very useful to have and has prevented numerous possible accident events when backing up... First thing I do before backing up is to view the console screen for things that might be in the way.
Roy Ken