If this is a 30 day impound, then you drove it either without having a license, or, your license was suspended.
The registered owner will need to schedule an post-storage hearing with the impounding agency in order to get it out early ... IF they will let her get it out early. There are a few possibilities including criminal charges against you for auto theft.
First, she needs to schedule that hearing ASAP.
And your license will be yet again suspended ... and you may go to jail.
EDIT: To be clear, YOU cannot have a post-storage hearing, only the registered owner or his or her designated representative. Understand that the fees can go up fast. It could cost more than $1,800 after 30 days. If the owner does not yet know the car is in impound, someone had better tell her before she gets the notification in the mail, or, receives notice that it is being put up for lien sale (that notice will likely go out after 10 days advising what will happen if arrangements are not made prior to day 30). If she gets surprised by all of this, you can pretty much guarantee that she will seek criminal charges against you for auto theft.