Removing your name from the title is one of a few ways to avoid liability. You can alternatively file a Notice of Transfer and Release of Liability, which is similar to a quitclaim.
The CVC covers liability for vehicles. CVC 5602 is particularly relevant:
5602. An owner who has made a bona fide sale or transfer of a vehicle and has delivered possession of the vehicle to a purchaser is not, by reason of any of the provisions of this code, the owner of the vehicle so as to be subject to civil liability or criminal liability for the parking, abandoning, or operation of the vehicle thereafter by another when the selling or transferring owner, in addition to that delivery and that bona fide sale or transfer, has fulfilled either of the following requirements:
- (a) He or she has made proper endorsement and delivery of the certificate of ownership as provided in this code.
- (b) He or she has delivered to the department or has placed in the United States mail, addressed to the department, either of the following documents:
- (1) The notice as provided in subdivision (b) of Section 4456 or Section 5900 or 5901.
- (2) The appropriate documents and fees for registration of the vehicle to the new owner pursuant to the sale or transfer.
And here's the relevant part of CVC 5900 which it refers to:
5900. (a) Whenever the owner of a vehicle registered under this code sells or transfers his or her title or interest in, and delivers the possession of, the vehicle to another, the owner shall, within five calendar days, notify the department of the sale or transfer giving the date thereof, the name and address of the owner and of the transferee, and the description of the vehicle that is required in the appropriate form provided for that purpose by the department.
I believe the California DMV's Notice of Transfer and Release of Liability is the above-mentioned "appropriate form provided for that purpose by the department."
Note the five calendar day requirement. Hopefully your ex wife took possession of the car less than five days ago?