It is your car until you sign it off, if it is taken from your driveway without your permission they have stolen it. They may just bluff you out by getting you to sign a receipt in which case you are at their mercy for a settlement.
Always have the car towed to your residence unless it is total loss, when it ends up in some pound and you want to part the car out the storage fees will not make it worthwhile as they have you by the shorts. You have the right to decide where it is towed to, some cops get kick backs for having it towed to a certain place. This is in Canada, most other places have similar laws. It is your car until you sign it over.