Not sure about the viofo, i will assume they are like the SG power supplies i am used to handling, if they are then the overall length is 3.8 meters / 12.5 feet.
I can only imagine that if you drive one of the good old US boat sized cars will this be a issue, you can always extend the cable on the 12 V side of things, it is not advisable to extend the 5 V / USB side of things.
You can also get cigarette lighter extensions, or just the female 12 V plug with ? length of wire.
With the viofo power supplies i cant recall if they have the PSU in the cigarette lighter plug itself or like SG have that take place in a little box a bit up the wire.
If you need to extend things i would tap into one of the cars fuses for that, then you have your lighter socket free for other stuff. i did this myself a few years ago putting a 3 way 12 V splitter in the boot of my car as back then we used single cameras as there was no good dual channel systems.
And i tried using a long USB wire, resulting in me getting rear ended and not getting a recording of that from my rear camera.
