I stayed and worked in France for 18 months, zipping home once or twice a month.
Was flashed a few times, nothing ever came of it. Consider also that the French cameras are designed to reveal the face of the driver only.
As we are sitting on the other side of the car, I believe our faces are obscured anyway.
Either way, I did use to get a move on, heading back to Calais, and never got hastled.
I use to like those paege, nice and clear.
So, don't sweat-it, you should be Ok, but that isn't license to go mad.
As others have posted, if they actually stop you, then its a fine. If you don't have the cash, they drive you to the nearest cash point take your money and then leave you at the cash point 😯
Very unlikely to take you back to your car.
L