So sad !
Take contact with a french lawyer...in any case it could be helpful.
We have a law against " private property privation" , your lawyer could ask a " referé" judgment. It's a speed up procedure for emergency case.
Explain that you, or your wife, needs this car...for work, or anything, if it's justified you could get a quick decision of justice department to get back your property.
I hope this situation will end quickly