Not often and not even from one of my 6 cameras in the car, but you do have to "reset" the FAT on the memory card once in a while with a fresh format on PC or in camera or both, and i do that about every 3-4 weeks, but do take into account i only drive like 1.5 hour every 2-3 days and all my memory cards are 64 Gb or 128 Gb.
When something happen i want to put on youtube i just make a mental note of the time and place, and then grab that off 1-2 or 3 cameras when i get home.
And when i have the memory card in the reader i also make sure the files on the memory cards correspond to my latest drives, and i make sure all last files in sessions can launch in a player on my PC, and then i also do the same to random files across the card.
This verification and copy of a single 3 minute file i need for youtube take me about 5 - 6 minutes for a 64 Gb card, dont play the whole files i look at, just that they can launch in player on PC, and if they can do that then the rest of the 3 minute file is properly also alright.